Index Modulations, in the form of Spatial Modulation or Polarized Modulation, are gaining traction for both satellite and terrestrial next generation communication systems. Adaptive Spatial Modulation based links are needed to fully exploit the transmission capacity of time-variant channels. The adaptation of code and/or modulation requires a real-time evaluation of the channel achievable rates. Some existing results in the literature present a computational complexity which scales quadratically with the number of transmit antennas and the constellation order. Moreover, the accuracy of these approximations is low and it can lead to wrong Modulation and Coding Scheme selection. In this work we apply a Multilayer Feedforward Neural Network to compute the achievable rate of a generic Index Modulation link. The case of two antennas/polarizations is analyzed in depth, showing not only a one-hundred fold decrement of the Mean Square Error in the estimation of the capacity as compared with existing analytical approximations, but also a fifty times reduction of the computational complexity. Moreover, the extension to an arbitrary number of antennas is explained and supported with simulations. More generally, neural networks can be considered as promising candidates for the practical estimation of complex metrics in communication related settings.

%B IEEE Transactions on Communications %@ 1558-0857 %G eng %R https://doi.org/10.1109/TCOMM.2020.2974215 %0 Conference Paper %B IEEE Int. Conf. Acoustics, Speech and Signal Processing (ICASSP) %D 2020 %T Optimal window design for W-OFDM %A Khawar Hussain %A R. López-Valcarce %K spectrum shaping %K winter %XWindowing is an effective approach to reduce out-of-band radiation (OBR) in multicarrier systems in order to avoid adjacent channel interference. However, commonly used window functions are chosen in an ad hoc manner and fixed. We present an optimal window design for windowed-OFDM minimizing OBR within a given frequency region. The proposed technique is flexible in that it allows to specify the range of frequencies involved in the minimization and to apply spectral weighting. The optimal window can be computed offline.

%B IEEE Int. Conf. Acoustics, Speech and Signal Processing (ICASSP)
%8 05/2020
%G eng
%1 Accepted.

%0 Conference Paper %B 45th International Conference on Acoustics, Speech, and Signal Processing (ICASSP) %D 2020 %T Resource Management in the multibeam NOMA-based satellite downlink %A Tomás Ramírez %A Carlos Mosquera %B 45th International Conference on Acoustics, Speech, and Signal Processing (ICASSP) %G eng %0 Journal Article %J IEEE Transactions on Information Forensics and Security %D 2020 %T Video Integrity Verification and GOP Size Estimation via Generalized Variation of Prediction Footprint %A David Vázquez-Padín %A Marco Fontani %A Dasara Shullani %A Fernando Pérez-González %A Alessandro Piva %A Mauro Barni %K B-frames %K double compression detection %K GOP size estimation %K rate distortion optimization %K video forensics %XThe Variation of Prediction Footprint (VPF), formerly used in video forensics for double compression detection and GOP size estimation, is comprehensively investigated to improve its acquisition capabilities and extend its use to video sequences that contain bi-directional frames (B-frames). By relying on a universal rate-distortion analysis applied to a generic double compression scheme, we first explain the rationale behind the presence of the VPF in double compressed videos and then justify the need of exploiting a new source of information such as the motion vectors, to enhance the VPF acquisition process. Finally, we describe the shifted VPF induced by the presence of B-frames and detail how to compensate the shift to avoid misguided GOP size estimations. The experimental results show that the proposed Generalized VPF (G-VPF) technique outperforms the state of the art, not only in terms of double compression detection and GOP size estimation, but also in reducing computational time.

%B IEEE Transactions on Information Forensics and Security %V 15 %P 1815-1830 %8 12/2019 %G eng %N 1 %& 1815 %0 Conference Paper %B 16th International Symposium on Wireless Communication Systems (ISWCS) %D 2019 %T Analog beamforming for full-duplex millimeter wave communication %A R. López-Valcarce %A Nuria González-Prelcic %K full-duplex %K mmWave %K winter %XFull-duplex (FD) communication has the potential for significant improvements in spectral efficiency, as long as the problem of self-interference (SI) can be overcome. For millimeter wave (mmWave) systems with large antenna arrays, beamforming based SI mitigation is attractive because of the large number of degrees of freedom available. Previously proposed precoder-combiner designs, however, suffer from a large performance loss under the hardware-constrained architectures required for operation at mmWave. In this context, we develop a new algorithm for the design of constant-amplitude analog precoders and combiners of an FD mmWave single-stream bidirectional link, significantly reducing the aforementioned performance loss.

%B 16th International Symposium on Wireless Communication Systems (ISWCS) %C Oulu, Finland %8 08/2019 %G eng %0 Conference Paper %B 16th International Symposium on Wireless Communication Systems (ISWCS) %D 2019 %T Beamformer design for full-duplex amplify-and-forward millimeter wave relays %A R. López-Valcarce %A Nuria González-Prelcic %K full-duplex %K mmWave %K winter %XWe consider the design of Amplify & Forward Full-Duplex (FD) relay-assisted communication systems. The FD mode has potential for significant improvements in spectral efficiency, but it suffers from large self-interference (SI) levels.

Beamforming-based SI mitigation is attractive for millimeter wave (mmWave) systems due to the large number of degrees of freedom available with large antenna arrays. We first develop an all-digital beamformer design by imposing a zero-forcing constraint on SI, performing quasi-optimally in terms of spectral efficiency. The design is then modified to fit the hardware-related constraints usually found when operating at mmWave, so that the beamformers can be implemented in the analog domain by using phase shifters, with an acceptable performance loss.

%B 16th International Symposium on Wireless Communication Systems (ISWCS) %C Oulu, Finland %8 08/2019 %G eng %0 Conference Paper %B 16th International Symposium on Wireless Communication Systems (ISWCS) %D 2019 %T Deep Learning Assisted Rate Adaptation in Spatial Modulation Links %A Anxo Tato %A Carlos Mosquera %K Deep Learning %K link adaptation %K Machine Learning %K Spatial Modulation %XThe adaptation of Spatial Modulation based links to the channel conditions is challenged by the complicated dependence between performance (either error rate metrics or theoretically achievable rates) and the multiple antenna channel description. In this paper a coding rate selection mechanism is presented based on a carefully selected set of channel features and the proper training of a deep neural network, which all together can satisfy a given error rate bound.

%B 16th International Symposium on Wireless Communication Systems (ISWCS) %C Oulu (Finland) %G eng %0 Conference Paper %B 34th Annual ACM Symposium on Applied Computing, SAC 2019 %D 2019 %T Dynamic Attribute-Based Privacy-Preserving Genomic Susceptibility Testing %A Mina Namazi %A Cihan Eryonucu %A Erman Ayday %A Fernando Pérez-González %B 34th Annual ACM Symposium on Applied Computing, SAC 2019 %C Limassol, Cyprus %8 04/2019 %G eng %0 Conference Paper %B XoveTIC %D 2019 %T Efficient PRNU Matching in the Encrypted Domain %A Alberto Pedrouzo-Ulloa %A Miguel Masciopinto %A Juan Ramón Troncoso-Pastoriza %A Fernando Pérez-González %K camera attribution forensic analyzer %K digital media forensics %K lattice-based cryptosystems %K Photoresponse Non-Uniformity %B XoveTIC %I MDPI %C A Coruña, Spain %G eng %0 Book Section %B Data Fusion in Wireless Sensor Networks: A statistical signal processing perspective %D 2019 %T Expectation–maximisation based distributed estimation in sensor networks %A R. López-Valcarce %A Alba Pagès-Zamora %K winter %K wsn %XEstimating the unknown parameters of a statistical model based on the observations collected by a sensor network is an important problem with application in multiple fields. In this setting, distributed processing, by which computations are carried out within the network in order to avoid raw data transmission to a fusion centre, is a desirable feature resulting in improved robustness and energy savings. In the presence of incomplete data, the expectation-maximisation (EM) algorithm is a popular means to iteratively compute the maximum likelihood (ML) estimate. It has found application in diverse fields such as computational biology, anomaly detection, speech segmentation, reinforcement learning, and motion estimation, among others. In this chapter we will review the formulation of the centralised EM estimation algorithm as a starting point and then discuss distributed versions well suited for implementation in sensor networks. The first class of these distributed versions requires specialised routing through the network in terms of a linear or circular path visiting all nodes, whereas the second class does away with this requirement by using the concept of network consensus to diffuse information through the network. Our focus will be on a relevant sensor network application, in which the parameter of a linear model is to be estimated in the presence of an unknown number of randomly malfunctioning sensors.

%B Data Fusion in Wireless Sensor Networks: A statistical signal processing perspective %I The Institution of Engineering and Technology (IET) %C London, UK %P 201-230 %@ 978-1-78561-584-9 %G eng %& 9 %0 Conference Paper %B 2nd XoveTIC Conference %D 2019 %T Flexible spectral precoding for OFDM systems %A Khawar Hussain %A R. López-Valcarce %K spectrum shaping %K winter %XSpectral precoding is a popular approach to reduce out-of-band radiation (OBR) in

multicarrier systems in order to avoid adjacent channel interference. However, it introduces

distortion in the data, appropriate decoding is required at the receiver side. Thus, trading off

between implementation complexity, OBR reduction and error rate is important. We present a novel

linear precoder design with flexibility to trade off OBR reduction, precoding/decoding complexity,

and error rate at the receiver. Moreover, the constraint can be imposed on each subcarrier individually

to provide more flexibility. The precoding matrices have low rank, which translates into significant

computational savings. In this way, the requirements of different systems can be satisfied with

varying complexity levels

%B 2nd XoveTIC Conference
%C A Coruña (Spain)
%8 09/2019
%G eng
%R 10.3390/proceedings2019021024
%0 Conference Paper
%B IEEE Int. Conf. Acoustics, Speech and Signal Processing (ICASSP)
%D 2019
%T Flexible spectral precoding for sidelobe suppression in OFDM systems
%A Khawar Hussain
%A Ana Lojo
%A R. López-Valcarce
%K spectrum shaping
%K winter
%X Spectral precoding is a popular approach to reduce out-of-band radiation (OBR) in multicarrier systems in order to avoid adjacent channel interference. Since precoding will introduce signal distortion, appropriate decoding is required at the receiver side. We present a novel linear precoder design with flexibility to trade off OBR reduction, precoding/decoding complexity, and error rate at the receiver. The precoding matrices have low rank, which translates into significant computational savings. In this way, the requirements of different systems can be satisfied with varying complexity levels.

%B IEEE Int. Conf. Acoustics, Speech and Signal Processing (ICASSP) %I IEEE %C Brighton, UK %P 4789 - 4793 %8 04/2019 %G eng %R 10.1109/ICASSP.2019.8683162 %0 Conference Paper %B IEEE Int. Conf. Acoustics, Speech and Signal Processing (ICASSP) %D 2019 %T Frequency-selective hybrid precoding and combining for mmWave MIMO systems with per-antenna power constraints %A Javier Rodríguez-Fernández %A R. López-Valcarce %A Nuria González-Prelcic %K mmWave %K winter %XConfiguring hybrid precoders and combiners is the main challenge to be solved to operate at millimeter wave (mmWave) frequencies. The use of hybrid architectures imposse hardware constraints on the analog precoder that need to be carefully dealt with. In this paper, we develop hybrid precoders and combiners aiming at minimizing the Euclidean distance with respect to the approximate all-digital precoders and combiners maximizing the spectral efficiency under per-antenna power constraints. Numerical results demonstrate the effectiveness of the proposed design method, whose performance is close to that of the all-digital solution.

%B IEEE Int. Conf. Acoustics, Speech and Signal Processing (ICASSP) %I IEEE %C Brighton, UK %P 4794-4798 %8 04/2019 %G eng %R 10.1109/ICASSP.2019.8683831 %0 Thesis %D 2019 %T Homomorphic Lattice Cryptosystems for Secure Signal Processing %A Alberto Pedrouzo-Ulloa %I University of Vigo %C Vigo %G eng %0 Journal Article %J IEEE Transactions on Information Forensics and Security %D 2019 %T Improving PRNU Compression Through Preprocessing, Quantization, and Coding %A L. Bondi %A P. Bestagini %A Fernando Pérez-González %A S. Tubaro %B IEEE Transactions on Information Forensics and Security %V 14 %P 13 %8 03/2019 %G eng %N 3 %& 608 %0 Thesis %B Universidade de Vigo %D 2019 %T Link Adaptation Techniques for Future Terrestrial and Satellite Communications %A Anxo Tato %XThe increasing demand of access to data from the users and the enormous number of connected devices requires to enhance the capacity of the wireless networks. They must provide a higher throughput to serve all the requested traffic and they must accommodate the vast number of the Internet of the Things (IoT) devices. In this context, this thesis focus its attention on three different scenarios which have in common that they are a future evolution of current terrestrial and satellite communications systems. These scenarios are Mobile Satellite Systems (MSS), Fixed Satellite Systems (FSS) and next generation 5G networks.

The adoption of Dual Polarization (DP) in MSS along with Multiple Input Multiple Output (MIMO) signal processing techniques allows to double the capacity of previous systems with the same bandwidth and transmit power. On the other hand, the shift to more aggressive frequency reuse patterns in FSS can also provide remarkable gains in the capacity of High Throughput Satellites (HTS) for offering BroadBand Satellite Services (BBS). Linear precoding stands out as a technique to cope with the high level of interference which arises in this scenario. Lastly, energy efficient modulation schemes, like Spatial Modulation (SM) and its many variants, are being proposed for increasing the capacity of future 5G networks since they represent a good trade-off between spectral efficiency, energy efficiency and transmitter complexity.

Adaptive Coding and Modulation (ACM) technology is omnipresent in most of the communication standards since it enables a better exploitation of the system capacity by means of the adaptation of the Modulation and Coding Scheme (MCS). The link adaptation algorithm is responsible for selecting the optimum MCS, as well as other physical layer parameters in some cases, to adapt the transmission bit rate according to the instantaneous channel capacity of the time variant channel. Thus, link adaptation algorithms permit to increase the spectrum efficiency and guarantee a robust communication, adapting the level of redundancy of the coded information bits and the ruggedness of the modulation scheme.

In this thesis, several link adaptation algorithms are proposed for the three considered scenarios and its effectiveness is supported with simulations. Furthermore, an experimental validation of some algorithms is provided using a real satellite link, implemented with Software Defined Radio (SDR) technology. It is also studied how the carrier detection errors in the Channel State Information (CSI) affect linear precoding in FSS. The errors in the users Signal to Interference and Noise Ratio (SINR) that the gateway calculates to allocate MCS to the users is analyzed statistically and geographically. Moreover, a link adaptation algorithm with an adaptive margin per user is shown to allow a robust communication in the presence of SINR errors whereas the throughput of the system is barely compromised. In addition, a new method for making capacity calculations in SM and Generalized SM systems based on a neural network is proposed, which improves both accuracy and computational complexity with regard to the existing analytical approximations in the literature. With regard to MSS using DP, an adaptation mechanism is proposed in order to select the optimum MIMO mode and MCS which offer the highest throughput. Simulation results in a maritime mobile satellite channel show the dependence of the optimum MIMO mode with the average Signal to Noise Ratio (SNR), and how the spectral efficiency can be maximized whereas a target outage probability can be guaranteed. Lastly, the adaptation in SM systems is also addressed and several methods for deciding the coding rate in SM are given. These include the computation of the capacity prior to the adaptation, and also the use of a deep neural network. The latter offers very good results, with a spectral efficiency very close to the maximum achievable value.

In practice, data gathered by wireless sensor networks often belongs in a low-dimensional subspace, but it can present missing as well as corrupted values due to sensor malfunctioning and/or malicious attacks. We study the problem of Maximum Likelihood estimation of the low-rank factors of the underlying structure in such situation, and develop an Expectation-Maximization algorithm to this purpose, together with an effective initialization scheme. The proposed method outperforms previous schemes based on an initial faulty sensor identification stage, and is competitive in terms of complexity and performance with convex optimization-based matrix completion approaches.

%B European Signal Processing Conference (EUSIPCO) %C A Coruña, Spain %8 09/2019 %G eng %0 Journal Article %J Mechanical Systems and Signal Processing %D 2019 %T Maximally stationary window design for overlap-add based random vibration synthesis %A Damián González %A R. López-Valcarce %K random vibration %XThe accurate synthesis of realistic waveforms conforming to certain specica-

tions is a fundamental step in random vibration testing. Since real-time imple-

mentation of digital signal processing systems for random vibration and noise

synthesis necessarily operates frame by frame, the overlap-add (OLA) method,

by which frames are windowed and overlapped, is widely used in practice to

avoid artifacts at frame boundaries. When a wide-sense stationary random

signal is desired, however, the OLA method presents a shortcoming, because

the inherent periodicity of the frame-by-frame process unavoidably produces a

cyclostationary signal, i.e., its statistics present an undesired periodic behav-

ior. We analyze the impact of the window coecients in the cyclostationarity

properties of the synthetic process, and then present algorithms for window de-

sign with the goal of maximizing a measure of its stationarity, considering both

second- and fourth-order statistical properties. The proposed designs are shown

to signicantly improve the stationarity properties when compared to commonly

used windows.

%B Mechanical Systems and Signal Processing
%V 122
%P 642-657
%8 05/2019
%G eng
%R 10.1016/j.ymssp.2018.12.038
%0 Journal Article
%J Signal Processing
%D 2019
%T MMSE filter design for Full-Duplex filter-and-forward MIMO relays under limited dynamic range
%A Emilio Antonio-Rodríguez
%A Stefan Werner
%A R. López-Valcarce
%A Risto Wichman
%K full-duplex
%K winter
%X We study the problem of optimizing the end-to-end performance of a full-duplex filter-and-forward MIMO relay link, consisting

of a source, a relay, and a destination node, by employing linear filtering at each node. The system model accounts for multipath

propagation and self-interference at the relay, as well as transmitter impairments and limited dynamic range at every node. The

design accommodates signals with arbitrary spectra and includes the direct link between the source and destination nodes. Under

the minimum mean square error criterion, the resulting non-convex problem is approximated by a sequence of convex problems

and solved by means of an alternating minimization method. Linear constraints allocate some of the degrees of freedom in the relay

to guarantee a sufficiently small residual self-interference. Simulations quantify the impact of degrees of freedom, the dynamic

range, and the balance between direct and relay paths on the link performance.

%B Signal Processing
%V 156
%P 208-219
%8 03/2019
%G eng
%R doi.org/10.1016/j.sigpro.2018.11.001
%0 Conference Paper
%B 27th European Signal Processing Conference (EUSIPCO)
%D 2019
%T Neural Network Aided Computation of Generalized Spatial Modulation Capacity
%A Anxo Tato
%A Carlos Mosquera
%A Pol Henarejos
%A Ana Pérez-Neira
%K Generalized Spatial Modulation
%K Index Modulations
%K Machine Learning
%K Multilayer Feedforward Neural Network
%K Polarized Modulation
%X Generalized Spatial Modulation (GSM) is being considered for future high-capacity and energy efficient terrestrial networks. A variant such as Polarized Modulation (PMod) has also a role in Dual Polarization Mobile Satellite Systems. The implementation of adaptive GSM systems requires fast methods to evaluate the channel dependent GSM capacity, which amounts to solve multi-dimensional integrals without closed-form solutions. For this purpose, we propose the use of a Multilayer Feedforward Neural Network and an associated feature selection algorithm. The resulting method is highly accurate and with much lower complexity than alternative numerical methods.

%B 27th European Signal Processing Conference (EUSIPCO) %C A Coruña (Spain) %G eng %0 Conference Paper %B European Signal Processing Conference (EUSIPCO) %D 2019 %T OFDM spectral precoding with per-subcarrier distortion constraints %A Khawar Hussain %A R. López-Valcarce %K spectrum shaping %K winter %XSpectral precoding is effective in reducing out-of-band radiation

(OBR) in multicarrier systems, but it introduces distortion

in the data, requiring a suitable decoder at the receiver.

Thus, trading off OBR reduction, implementation complexity,

and error rate is of paramount importance. We present a precoder

design which minimizes OBR under constraints on the

distortion at each individual data subcarrier. By judiciously

choosing the distortion profile, the decoding task can be significantly

alleviated, with a sizable improvement in terms of

implementation complexity with respect to previous designs.

%B European Signal Processing Conference (EUSIPCO)
%C A Coruña, Spain
%8 09/2019
%G eng
%0 Journal Article
%J IEEE Transactions on Wireless Communications
%D 2019
%T Partial-Duplex Amplify-and-Forward Relaying: Spectral Efficiency Analysis under Self-Interference
%A R. López-Valcarce
%A C. Mosquera
%K full-duplex
%K myrada
%K winter
%X We propose a novel mode of operation for Amplify-and-

Forward relays in which the spectra of the relay input and

output signals partially overlap. This partial-duplex relaying mode

encompasses half- and full-duplex as particular cases. By viewing

the partial-duplex relay as a bandwidth-preserving Linear

Periodically Time-Varying system, a spectral efficiency analysis

under self-interference is developed. In contrast with previous

works, self-interference is regarded as a useful informationbearing

component rather than simply assimilated to noise. This

approach reveals that previous results regarding the impact of

self-interference on (full-duplex) relay performance are overly

pessimistic. Based on a frequency-domain interpretation of the

effect of self-interference, a number of suboptimal decoding

architectures at the destination node are also discussed. It is found

that the partial-duplex relaying mode may provide an attractive

tradeoff between spectral efficiency and receiver complexity.

%B IEEE Transactions on Wireless Communications
%V 18
%P 2271-2285
%8 04/2019
%G eng
%N 4
%R 10.1109/TWC.2019.2902390
%0 Conference Paper
%B EUSIPCO
%D 2019
%T Prediction Residue Analysis in MPEG-2 Double Compressed Video Sequences
%A David Vázquez-Padín
%A Fernando Pérez-González
%K double compression detection
%K GOP size estimation
%K MPEG-2
%K prediction residue analysis
%K video forensics
%X In video forensics, the study of the prediction residue across successive frames is key to verify the integrity of digital videos. Focusing on an MPEG-2 double compression scheme, we analyze how the variance of the prediction residue evolves during the second compression depending on the type of frame (either I or P) employed in the first encoding and exploring different compression strengths and deadzone widths for quantization. This analysis reveals that the width of the quantizer deadzones actually affects the performance of existing methods based on the Variation of Prediction Footprint (VPF) for double compression detection and Group Of Pictures (GOP) size estimation. The predicted behavior from the theoretical characterization of the prediction residue is confirmed through experimental results with real video sequences.

%B EUSIPCO %C A Coruña, Spain %P 1109-1113 %8 09/2019 %G eng %0 Conference Paper %B IEEE European Symposium on Security and Privacy (EuroS&P) %D 2019 %T Rethinking Location Privacy for Unknown Mobility Behaviors %A Simon Oya %A Carmela Troncoso %A Fernando Pérez-González %B IEEE European Symposium on Security and Privacy (EuroS&P) %G eng %0 Conference Paper %B ACM Information Hiding and Multimedia Security Workshop (IH&MMSec) %D 2019 %T Revisiting Multivariate Lattices for Encrypted Signal Processing %A Alberto Pedrouzo-Ulloa %A Juan Ramón Troncoso-Pastoriza %A Fernando Pérez-González %K homomorphic encryption %K Lattice-Based Cryptography %K Multidimensional Signal Processing %K Secure Signal Processing %B ACM Information Hiding and Multimedia Security Workshop (IH&MMSec) %I ACM %C Paris, France %G eng %0 Conference Proceedings %B 2nd XoveTIC Conference %D 2019 %T Solving self-interference issues in a Full-Duplex radio transceiver %A Miguel Franco-Martinez %A Francisco-Javier Martinez-Alonso %A R. López-Valcarce %K full-duplex %K winter %XMost wireless devices transmit and receive at different spectrum frequency bands. This

approach is no longer optimal due to increasing electromagnetic exhaustion. Besides, interference

among all present and future working services should be negligible. A full-duplex scheme using

the same band for simultaneous uplink and downlink is a huge step towards solving this issue.

However, sharing the same frequency band involves a large interference of transmitted signal over

received signal. To fix this problem, we propose the usage of a hybrid multistage cancellation system,

consisting of an analog cancellation setup at RF frequencies and a baseband digital cancellation stage.

%B 2nd XoveTIC Conference
%C A Coruña (Spain)
%8 09/2019
%G eng
%R 10.3390/proceedings2019021035
%0 Conference Paper
%B 2nd XoveTIC Conference
%D 2019
%T Spatial Modulation for Beyond 5G Communications: Capacity Calculation and Link Adaptation
%A Anxo Tato
%A Carlos Mosquera
%K 5G
%K adaptive coding and modulation
%K Deep Learning
%K link adaptation
%K Machine Learning
%K neural networks
%K Spatial Modulation
%B 2nd XoveTIC Conference
%C A Coruña (Spain)
%G eng
%0 Conference Paper
%B 2019 53rd Asilomar Conference on Signals, Systems, and Computers
%D 2019
%T Spatial Modulation Link Adaptation: a Deep Learning Approach
%A Anxo Tato
%A Carlos Mosquera
%B 2019 53rd Asilomar Conference on Signals, Systems, and Computers
%C California
%G eng
%0 Thesis
%D 2019
%T A Statistical Approach to the Design of Privacy-Preserving Services
%A Simon Oya
%G eng
%0 Report
%D 2019
%T Technical Report: MPEG-2 Prediction Residue Analysis
%A David Vázquez-Padín
%A Fernando Pérez-González
%I University of Vigo
%G eng
%0 Conference Paper
%B 36th International Communications Satellite Systems Conference (ICSSC)
%D 2018
%T Adjacent Beams Resource Sharing to Serve Hot Spots : A Rate Splitting Approach
%A Tomás Ramírez
%A Carlos Mosquera
%A Màrius Caus
%A Adriano Pastore
%A Nader Alagha
%A Nele Noels
%X This work addresses the uneven traffic demand scenario in multi-beam satellite systems, in which a hot-spot beam

is surrounded by cold beams. After partitioning the hotspot beam in different sectors, resource pulling from cold

neighbouring beams is allowed following an aggressive frequency-reuse scheme. As a consequence, the level of

the co-channel interference within the hot-spot beam increases. A scheme known as Non-Coherent Rate-Splitting (NCRS)

is employed to cope with this interference, based on the exclusive use of magnitude channel state information at the transmitter (CSIT).

The receiver complexity is increased with respect to full CSIT precoding schemes, which are considered for benchmarking purposes. Different NCRS strategies are analyzed and compared with several partial and full CSIT schemes. The proposed solution not only shows an improvement with respect to partial CSIT benchmarks, but also displays a competitive performance against full CSIT precoders.

%B 36th International Communications Satellite Systems Conference (ICSSC)
%C Niagara Falls, Canada
%8 10/2018
%G eng
%0 Conference Paper
%B IEEE International Workshop on Information Forensics and Security (WIFS)
%D 2018
%T Camera Attribution Forensic Analyzer in the Encrypted Domain
%A Alberto Pedrouzo-Ulloa
%A Miguel Masciopinto
%A Juan Ramón Troncoso-Pastoriza
%A Fernando Pérez-González
%B IEEE International Workshop on Information Forensics and Security (WIFS)
%I IEEE
%C Hong Kong
%G eng
%1 IEEE WIFS 2018 Best Paper Award

%0 Conference Paper %B ICCASP, IEEE International Conference on Acoustics, Speech, and Signal Processing %D 2018 %T Channel dependent Mutual Information in Index Modulations %A Pol Henarejos %A Ana Pérez-Neira %A Anxo Tato %A Carlos Mosquera %XMutual Information is the metric that is used to perform link adaptation, which allows to achieve rates near capacity. The computation of adaptive transmission modes is achieved by employing the mapping between the Signal to Noise Ratio and the Mutual Information. Due to the high complexity of the computation of the Mutual Information, this process is performed off-line via Monte Carlo simulations, whose results are stored in look-up tables. However, in Index Modulations, such as Spatial Modulation or Polarized Modulation, this is not feasible since the constellation and the Mutual Information are channel dependent and it would require to compute this metric at each time instant if the channel is time varying. In this paper, we propose different approximations in order to obtain a simple closed-form expression that allows to compute the Mutual Information at each time instant and thus, making feasible the link adaptation.

%B ICCASP, IEEE International Conference on Acoustics, Speech, and Signal Processing %G eng %0 Journal Article %J IEEE Transactions on Wireless Communication %D 2018 %T Distributed Precoding Systems in Multi-Gateway Multibeam Satellites: Regularization and Coarse Beamforming %A Carlos Mosquera %A R. López-Valcarce %A Tomás Ramírez %A Vahid Joroughi %B IEEE Transactions on Wireless Communication %G eng %0 Conference Paper %B 15th International Symposium on Wireless Communication Systems (ISWCS) %D 2018 %T Exploratory Analysis of Superposition Coding and Rate Splitting for Multibeam Satellite Systems %A Màrius Caus %A Adriano Pastore %A Mònica Navarro %A Tomás Ramírez %A Carlos Mosquera %A Nele Noels %A Nader Alagha %A Ana I. Perez-Neira %B 15th International Symposium on Wireless Communication Systems (ISWCS) %C Lisbon, Portugal %G eng %0 Conference Paper %B 9th Advanced Satellite Multimedia Systems Conference (ASMS) and 15th Signal Processing for Space Communications Workshop (SPSC) %D 2018 %T Link Adaptation and Carriers Detection Errors in Multibeam Satellite Systems with Linear Precoding %A Anxo Tato %A Stefano Andrenacci %A Chatzinotas, S. %A Carlos Mosquera %XThe application of linear precoding at the gateway side enables broadband multibeam satellite systems to use more aggressive frequency reuse patterns increasing the overall capacity of future High Throughput Satellites (HTS). However, although some previous works about precoding consider imperfect CSIT (Chanel State Information at the Transmitter) adding some CSI estimation errors, that is not the main cause of CSI degradation. In practice, receivers can only detect and estimate a few coefficients of the CSI vector being the other nullified, replaced by zeros. This introduces errors in the SINR calculation by the gateway that lead to the assignment of Modulation and Coding Schemes (MCS) over the decoding possibilities of the users, increasing the rate of erroneous frames. In this work, the errors in the SINR calculation caused by the nullification of the CSI are analyzing statistically and geographically using a radiation diagram of 245 beams over Europe. Furthermore, a solution based on a link adaptation algorithm with a per user adaptive margin is proposed, helping to achieve the QEF (Quasi-error Free) target of DVB-S2X systems.

This work addresses the problem of determining whether two multivariate random time series have the same power spectral density

(PSD), which has applications, for instance, in physical-layer security and cognitive radio. Remarkably, existing detectors for this

problem do not usually provide any kind of optimality. Thus, we study here the existence under the Gaussian assumption of optimal

invariant detectors for this problem, proving that the uniformly most powerful invariant test (UMPIT) does not exist. Thus, focusing on

close hypotheses, we show that the locally most powerful invariant test (LMPIT) only exists for univariate time series. In the multivariate

case, we prove that the LMPIT does not exist. However, this proof suggests two LMPIT-inspired detectors, one of which outperforms

previously proposed approaches, as computer simulations show.

%B IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP)
%C Calgary, Canada
%G eng
%0 Conference Paper
%B 9th Advanced Satellite Multimedia Systems Conference (ASMS) and 15th Signal Processing for Space Communications Workshop (SPSC)
%D 2018
%T Message-Splitting for Interference Cancellation in Multibeam Satellite Systems
%A Tomás Ramírez
%A Carlos Mosquera
%A Màrius Caus
%A Adriano Pastore
%A Mònica Navarro
%A Nele Noels
%B 9th Advanced Satellite Multimedia Systems Conference (ASMS) and 15th Signal Processing for Space Communications Workshop (SPSC)
%C Berlin, Germany
%G eng
%0 Journal Article
%J Signal Processing
%D 2018
%T Parameter estimation in wireless sensor networks with faulty transducers: A distributed EM approach
%A Silvana Silva Pereira
%A R. López-Valcarce
%A Alba Pagès-Zamora
%K winter
%K wsn
%X We address the problem of distributed estimation of a vector-valued parameter performed by a wireless sensor network in the presence of noisy observations which may be unreliable due to faulty transducers. The proposed distributed estimator is based on the Expectation-Maximization (EM) algorithm and combines consensus and diffusion techniques: a term for information diffusion is gradually turned off, while a term for updated information averaging is turned on so that all nodes in the network approach the same value of the estimate. The proposed method requires only local exchanges of information among network nodes and, in contrast with previous approaches, it does not assume knowledge of the a priori probability of transducer failures or the noise variance. A convergence analysis is provided, showing that the convergent points of the centralized EM iteration are locally asymptotically convergent points of the proposed distributed scheme. Numerical examples show that the distributed algorithm asymptotically attains the performance of the centralized EM method.

%B Signal Processing %V 144 %P 226-237 %8 03/2018 %G eng %U https://authors.elsevier.com/a/1W90XbZX4rsob %R 10.1016/j.sigpro.2017.10.012 %0 Conference Paper %B 11th International Symposium on Communication Systems, Networks, and Digital Signal Processing. %D 2018 %T Practical Implementation of Link Adaptation with Dual Polarized Modulation (Best paper award) %A Anxo Tato %A Carlos Mosquera %A Pol Henarejos %A Ana Pérez-Neira %B 11th International Symposium on Communication Systems, Networks, and Digital Signal Processing. %G eng %1Best paper award

%0 Conference Paper %B European Signal Processing Conference (EUSIPCO) %D 2018 %T Putting the PRNU Model in Reverse Gear: Findings with Synthetic Signals %A Miguel Masciopinto %A Fernando Pérez-González %B European Signal Processing Conference (EUSIPCO) %C Rome, Italy %8 2018 %G eng %0 Conference Proceedings %B XoveTIC Congress %D 2018 %T Software Defined Radio: A Brief Introduction %A Anxo Tato %XIn this short article the concept of Software Defined Radio (SDR) is introduced and compared with the traditional radio. Then, a research project of atlanTTic center which used this technology was briefly presented and lastly, we include a reference to some dissemination

activities related with SDR to be developed shortly.

The first step in the definition of the specifications for the vibration tests of any automotive component

is the recording and evaluation of the properties of the input vibration during field measurements. In this

paper, we explore the properties of the vibration measured at the base of the driver seat when driving

through different surfaces, with the purpose of defining a model for non-Gaussian random vibration

testing. The recorded acceleration signals are first transformed to a 6 Degree of Freedom (DOF) space,

and then segmented into stationary sections that are later analyzed. The non-Gaussian nature of the

recorded vibration is demonstrated through different Gaussianity hypothesis tests, and the distribution of

the third and fourth order moments, as well as the crest factor, are computed and analyzed. The second-order

spectral content reveals significant correlation at specific frequencies, while the significance of

third order polyspectra is checked through hypothesis testing. Based on our observations, a practical

definition of the random process is proposed based on second-order spectral content, univariate kurtosis

and crest factor levels.

%B Int. Conf. on Noise and Vibration Engineering, ISMA-USD 2018
%C Leuven, Belgium
%8 09/2018
%G eng
%0 Conference Paper
%B 6th IEEE Global Conference on Signal and Information Processing
%D 2018
%T Symbol-Asynchronous Transmission In Multibeam Satellite User Down-Link: Rate Regions For Novel Superposition Coding Schemes
%A Nele Noels
%A Marc Moeneclaey
%A Tomás Ramírez
%A Carlos Mosquera
%A Màrius Caus
%A Adriano Pastore
%X We consider the forward link of a multibeam satellite system with high spectral reuse and the novel low-complexity transmission and detection strategies from ["“Exploratory analysis of superposition coding and rate splitting for multibeam satellite systems", ISWCS 2018]. More specifically, we study the impact of a time offset between the antenna beams that cooperate to simultaneously serve a given user. Assuming Gaussian signaling, we provide closed-form expressions for the achievable rate region. It is demonstrated that, in the absence of timing information at the gateway, this region is not affected by a time offset. Our numerical results further show that, in case timing is known at the gateway, an offset of half a symbol period at both user terminals is optimal in terms of spectral efficiency.

%B 6th IEEE Global Conference on Signal and Information Processing %G eng %0 Journal Article %J IEEE Trans. Signal Processing %D 2018 %T Testing equality of multiple power spectral density matrices %A David Ramírez %A Daniel Romero %A Javier Vía %A R. López-Valcarce %A Ignacio Santamaría %K cognitive radio %K winter %B IEEE Trans. Signal Processing %V 66 %P 6268-6280 %8 12/2018 %G eng %N 23 %R 10.1109/TSP.2018.2875884 %0 Conference Paper %B 22nd International Workshop on Smart Antennas (WSA) %D 2018 %T Two-Level Precoding for High Throughput Satellites with non-Cooperative Gateways %A Tomás Ramírez %A Carlos Mosquera %A Roberto López-Valcarce %B 22nd International Workshop on Smart Antennas (WSA) %G eng %0 Conference Paper %B ACM Conference on Computer and Communications Security (CCS) %D 2017 %T Back to the Drawing Board: Revisiting the Design of Optimal Location Privacy-preserving Mechanisms %A Simon Oya %A Carmela Troncoso %A Fernando Pérez-González %B ACM Conference on Computer and Communications Security (CCS) %G eng %0 Journal Article %J Digital Signal Processing %D 2017 %T CDMA-based Acoustic Local Positioning System for Portable Devices with Multipath Cancellation %A Fernando J. Alvarez %A Teodoro Aguilera %A R. López-Valcarce %K compass %K wsn %XThis paper presents an acoustic local positioning system (ALPS) suitable for indoor positioning

of portable devices such as smartphones or tablets, based on the transmission of high frequency

CDMA-coded signals from a fixed network of beacons. The main novelty of the proposed ALPS is

its capability to mitigate the effects of multipath propagation by performing an accurate estimation

of the Line-of-Sight Time-of-Flights (LOS-TOF) through the Matching Pursuit algorithm. Signal

detection, multipath cancellation and positioning estimation all take place within the portable device,

which provides a graphical representation of the updated position in less than a second. The

performance of the Matching Pursuit algorithm is analyzed in a real scenario and the results show

that the proposed method is capable to retrieve the multipath-free System Availability under strong

multipath conditions with SNR levels as low as 0 dB.

%B Digital Signal Processing
%V 62
%P 38-51
%8 03/2017
%G eng
%R 10.1016/j.dsp.2016.11.001
%0 Conference Paper
%B European Signal Processing Conference (EUSIPCO)
%D 2017
%T Defending Surveillance Sensor Networks Against Data-Injection Attacks via Trusted Nodes
%A R. López-Valcarce
%A Daniel Romero
%K winter
%K wsn
%X By injecting false data through compromised sensors, an adversary can drive the probability of detection in a sensor network-based spatial field surveillance system to arbitrarily low values. As a countermeasure, a small subset of sensors may be secured. Leveraging the theory of Matched Subspace Detection, we propose and evaluate several detectors that add robustness to attacks when such trusted nodes are available. Our results reveal the performance-security tradeoff of these schemes and can be used to determine the number of trusted nodes required for a given performance target.

%B European Signal Processing Conference (EUSIPCO)
%C Kos Island, Greece
%8 08/2017
%G eng
%0 Conference Paper
%B 2017 IEEE Workshop on Information Forensics and Security (WIFS)
%D 2017
%T Design of projection matrices for PRNU compression
%A L. Bondi
%A Fernando Pérez-González
%A P. Bestagini
%A S. Tubaro
%K acquisition time
%K cameras
%K computational complexity
%K data compression
%K defacto standard
%K design methodology
%K digital photo
%K forensics investigators
%K image coding
%K Image forensics
%K image sensors
%K image source identification
%K interpolation
%K matrix algebra
%K nearly-flat spectral characteristics
%K Performance evaluation
%K photo response nonuniformity
%K PRNU compression
%K probability
%K projection matrices
%K public image dataset
%K Signal to noise ratio
%K silicon sensor imperfections
%K specific camera sensor
%K weak multiplicative noise
%B 2017 IEEE Workshop on Information Forensics and Security (WIFS)
%P 1-6
%8 Dec
%G eng
%R 10.1109/WIFS.2017.8267652
%0 Conference Paper
%B 35th AIAA International Communications Satellite Systems Conference
%D 2017
%T Distributed Precoding Systems in Multi-Gateway Multibeam Satellites
%A Carlos Mosquera
%A R. López-Valcarce
%A Tomás Ramírez
%K precoding
%K satcom
%B 35th AIAA International Communications Satellite Systems Conference
%C Trieste,Italy
%8 10/2017
%G eng
%0 Journal Article
%J IEEE Transactions on Wireless Communications
%D 2017
%T FER Estimation in a Memoryless BSC with Variable Frame Length and Unreliable ACK/NAK Feedback
%A Alberto Rico-Alvariño
%A R. López-Valcarce
%A Carlos Mosquera
%A Robert W. Heath Jr.
%K adaptive signal processing
%K compass
%K Cramér-Rao bound (CRB)
%K frame error rate
%K myrada
%K winter
%X We consider the problem of estimating the frame error rate (FER) of a given memoryless binary symmetric channel by observing the success or failure of transmitted packets. Whereas FER estimation is relatively straightforward if all observations correspond to packets with equal length, the problem becomes considerably more complex when this is not the case. We develop FER estimators when

transmissions of different lengths are observed, together with the Cramer-Rao Lower Bound (CRLB). Although the main focus is on Maximum Likelihood (ML) estimation, we also obtain low complexity schemes performing close to optimal in some scenarios. In a second stage, we consider the case in which FER estimation is performed at a node different from the receiver, and incorporate the impairment of unreliable observations by considering noisy ACK/NAK feedback links. The impact of unreliable feedback is analyzed by means of the corresponding CRLB. In this setting, the ML estimator is obtained by applying the Expectation-Maximization algorithm to jointly estimate the error probabilities of the data and feedback links. Simulation results illustrate the benefits of the proposed estimators.

%B IEEE Transactions on Wireless Communications
%V 16
%P 3661 - 3673
%8 06/2017
%G eng
%N 6
%R 10.1109/TWC.2017.2686845
%0 Conference Paper
%B IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP)
%D 2017
%T Filter design for delay-based anonymous communications
%A Simon Oya
%A Fernando Pérez-González
%A Carmela Troncoso
%K adversarial signal processing
%K compass
%K Multimedia security
%K winter
%B IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP)
%G eng
%0 Conference Paper
%B Workshop on Privacy in the Electronic Society (WPES)
%D 2017
%T Is Geo-Indistinguishability what you are looking for?
%A Simon Oya
%A Carmela Troncoso
%A Fernando Pérez-González
%K adversarial signal processing
%K Multimedia security
%K winter
%B Workshop on Privacy in the Electronic Society (WPES)
%G eng
%0 Journal Article
%J IEEE Transactions on Signal Processing
%D 2017
%T Learning Power Spectrum Maps from Quantized Power Measurements
%A Daniel Romero
%A Seung-Jun Kim
%A Georgios Giannakis
%A R. López-Valcarce
%K cognitive radio
%K compass
%K compressed sensing
%K spectrum sensing
%K winter
%K wsn
%X Using power measurements collected by a network of low-cost sensors, power spectral density (PSD) maps are con-

structed to capture the distribution of RF power across space and frequency. Linearly compressed and quantized power measure-

ments enable wideband sensing at affordable implementation complexity using a small number of bits. Strengths of data- and model-

driven approaches are combined to develop estimators capable of incorporating multiple forms of spectral and propagation prior

information while fitting the rapid variations of shadow fading across space. To this end, novel nonparametric and semiparametric

formulations are investigated. It is shown that the desired PSD maps can be obtained using support vector machine-type solvers.

In addition to batch approaches, an online algorithm attuned to real-time operation is developed. Numerical tests assess the performance of the novel algorithms.

%B IEEE Transactions on Signal Processing
%V 65
%P 2547-2560
%8 05/2017
%G eng
%N 10
%R 10.1109/TSP.2017.2666775
%0 Conference Proceedings
%B 9th EAI International Conference on Wireless and Satellite Systems, WISATS
%D 2017
%T Link Adaptation Algorithms for Dual Polarization Mobile Satellite Systems
%A Anxo Tato
%A Pol Henarejos
%A Carlos Mosquera
%A Ana Pérez-Neira
%X The use of dual polarization in mobile satellite systems is

very promising as a means for increasing the transmission capacity. In this paper a system which uses simultaneously two orthogonal polarizations in order to communicate with the users is studied. The application of MIMO signal processing techniques along with Adaptive Coding and Modulation in the forward link can provide remarkable throughput gains up to 100 % when compared with the single polarization system. The gateway is allowed to vary the MIMO and Modulation and Coding Schemes for each frame. The selection is done by means of a link adaptation algorithm which uses a tunable margin to achieve a predefined target Frame Error Rate.

The stochastic representation of digital images through a two-dimensional autoregressive (2D-AR) model offers a proper way to approximate the empirical distribution of the eigenvalues coming from genuine images. By considering this model, we apply random matrix theory to analytically derive the asymptotic eigenvalue distribution of causal 2D-AR random fields that have undergone an upscaling operation with a particular interpolation kernel. This eigenvalue characterization is useful in developing new forensic techniques for image resampling detection since we can use theoretical bounds to drive the decision of detectors based on subspace decomposition. Moreover, experimental results with real images show that the obtained asymptotic limits turn out to be excellent approximations, even when working with images of small size.

%B International Tyrrhenian Workshop on Digital Communication 2017 %I Springer International Publishing %C Palermo, Italy %P 109-124 %8 09/2017 %G eng %0 Conference Paper %B IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP) %D 2017 %T Robust clustering of data collected via crowdsourcing %A Alba Pagès-Zamora %A Georgios Giannakis %A R. López-Valcarce %A Pere Gimenez-Febrer %K winter %K wsn %XCrowdsourcing approaches rely on the collection of multiple individuals to solve problems that require analysis of large data sets in a timely accurate manner. The inexperience of participants or annotators motivates well robust techniques. Focusing on clustering setups, the data provided by all annotators is suitably modeled here as a mixture of Gaussian components plus a uniformly distributed random variable to capture outliers. The proposed algorithm is based on the expectation-maximization algorithm and allows for soft assignments of data to clusters, to rate annotators according to their performance, and to estimate the number of Gaussian components in the non-Gaussian/Gaussian mixture model, in a jointly manner.

%B IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP) %C New Orleans %P 4014 - 4018 %8 03/2017 %G eng %R 10.1109/ICASSP.2017.7952910 %0 Conference Paper %B IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) %D 2017 %T Secure Genomic Susceptibility Testing based on Lattice Encryption %A Juan Ramón Troncoso-Pastoriza %A Alberto Pedrouzo-Ulloa %A Fernando Pérez-González %K adversarial signal processing %K compass %K Genomic Privacy %K homomorphic encryption %K Lattice-Based Cryptography %K Privacy Protection %B IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) %I IEEE %C New Orleans, USA %G eng %0 Journal Article %J IEEE Transactions on Information Forensics and Security %D 2017 %T Smart Detection of Line-Search Oracle Attacks %A Tondi, Benedetta %A Pedro Comesaña %A Fernando Pérez-González %A Barni, Mauro %B IEEE Transactions on Information Forensics and Security %V 12 %P 588-603 %8 03/2017 %G eng %N 3 %& 588 %0 Journal Article %J IEEE Transactions on Information Forensics and Security %D 2017 %T Statistical detection of JPEG traces in digital images in uncompressed formats %A Cecilia Pasquini %A Giulia Boato %A Fernando Pérez-González %B IEEE Transactions on Information Forensics and Security %V 12 %G eng %N Pending %0 Report %D 2017 %T Technical Report UV-TSC-DVP-19042017: Derivation of the Asymptotic Eigenvalue Distribution for Causal 2D-AR Models under Upscaling %A David Vázquez-Padín %A Fernando Pérez-González %A Pedro Comesaña %I University of Vigo %G eng %0 Conference Paper %B IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) %D 2017 %T Time-domain channel estimation for wideband millimeter wave systems with hybrid architecture %A Kiran Venugopal %A Ahmed Alkhateeb %A Robert W. Heath Jr. %A Nuria González-Prelcic %K compass %K mmWave %K myrada %XMillimeter wave (mm Wave) systems will likely employ large antennas at both the transmitter and receiver for directional beamforming. Hybrid analog/digital MIMO architectures have been proposed previously for leveraging both array gain and multiplexing gain, while reducing the power consumption in analog-to-digital converters. Channel knowledge is needed to design the hybrid precoders/combiners, which is difficult to obtain due to the large antenna arrays and the frequency selective nature of the channel. In this paper, we propose a sparse recovery based time-domain channel estimation technique for hybrid architecture based frequency selective mmWave systems. The proposed compressed sensing channel estimation algorithm is shown to provide good estimation error performance, while requiring small training overhead. The simulation results show that using multiple RF chains at the receiver and the transmitter further reduces the training overhead.

%B IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) %P 6193-6197 %8 03/2017 %G eng %0 Journal Article %J Signal Processing %D 2017 %T Wideband full-duplex MIMO relays with blind adaptive self-interference cancellation %A Emilio Antonio-Rodríguez %A Stefan Werner %A R. López-Valcarce %A Taneli Riihonen %A Risto Wichman %K adaptive signal processing %K compass %K full duplex %K winter %XWe develop adaptive self-interference cancellation algorithms for both filter-and-forward and decode-and-forward

multiple-input multiple-output relays. The algorithms are blind in the sense that they only exploit the spectral properties

of the transmitted signal to identify the self-interference channel, while dealing with frequency-selective channels and

arbitrary signal spectra. Our approach is non-intrusive in the sense that the algorithms can successfully identify, track,

and cancel the self-interference distortion while the relay is operating in its normal mode. We study the stationary

points of the algorithms and analyze under which conditions they achieve perfect cancellation of the self-interference.

Simulation results show that the algorithms provide residual self-interference levels below the noise floor by using

the time samples of only a few OFDM symbols.

%B Signal Processing
%V 130
%P 74-85
%8 01/2017
%G eng
%& 74
%R 10.1016/j.sigpro.2016.06.010
%0 Conference Paper
%B 8th Advanced Satellite Multimedia Systems Conference 14th Signal Processing for Space Communications Workshop
%D 2016
%T Advanced Signal Processing Techniques for Fixed and Mobile Satellite Communications
%A Pol Henarejos
%A Ana Pérez-Neira
%A Nicolò Mazzali
%A Carlos Mosquera
%K compass
%K full duplex
%K satcom
%B 8th Advanced Satellite Multimedia Systems Conference 14th Signal Processing for Space Communications Workshop
%8 09/2016
%G eng
%0 Conference Paper
%B IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP)
%D 2016
%T Array thinnig for antenna selection in millimeter wave MIMO systems
%A C. Rusu
%A Nuria González-Prelcic
%A R. W. Heath Jr
%K compass
%K mmWave
%B IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP)
%8 2016
%G eng
%0 Conference Paper
%B The 17th IEEE International workshop on Signal Processing advances in Wireless Communications (SPAWC)
%D 2016
%T Bandwidth Allocation in Partial Duplex Relaying
%A Carlos Mosquera
%A R. López-Valcarce
%K compass
%K full duplex
%K relay
%B The 17th IEEE International workshop on Signal Processing advances in Wireless Communications (SPAWC)
%C Edinburgh, UK
%8 07/2016
%G eng
%0 Conference Paper
%B International Conference on Availability, Reliability and Security (ARES)
%D 2016
%T Co-creating Security-and-Privacy-by-Design Systems
%A Sauro Vicini
%A Francesco Alberti
%A Nicolás Notario
%A Alberto Crespo
%A Juan Ramón Troncoso-Pastoriza
%A Alberto Sanna
%B International Conference on Availability, Reliability and Security (ARES)
%C Salzburg, Germany
%P 768-775
%8 09/2016
%G eng
%0 Journal Article
%J IEEE Signal Processing Magazine
%D 2016
%T Compressive Covariance Sensing: Structure-Based Compressive Sensing Beyond Sparsity
%A Daniel Romero
%A Dyonisius D Ariananda
%A Zhi Tian
%A Geert Leus
%K compass
%K compressed sensing
%X Compressed sensing deals with the reconstruction of signals

from sub-Nyquist samples by exploiting the sparsity of their

projections onto known subspaces. In contrast, the present

article is concerned with the reconstruction of second-order

statistics, such as covariance and power spectrum, even in

the absence of sparsity priors. The framework described here

leverages the statistical structure of random processes to

enable signal compression and offers an alternative perspective

at sparsity-agnostic inference. Capitalizing on parsimonious

representations, we illustrate how compression and reconstruction

tasks can be addressed in popular applications such

as power spectrum estimation, incoherent imaging, direction

of arrival estimation, frequency estimation, and wideband

spectrum sensing.

%B IEEE Signal Processing Magazine
%V 33
%P 78--93
%8 01/2016
%G eng
%N 1
%0 Journal Article
%J IEEE Transactions on Multimedia
%D 2016
%T Data Hiding Robust to Mobile Communication Vocoders
%A Reza Kazemi
%A Fernando Pérez-González
%A Mohamed Ali Akhaee
%A Fereydoon Behnia
%B IEEE Transactions on Multimedia
%V 18
%P 2345-2357
%8 12/2016
%G eng
%N 12
%R 10.1109/TMM.2016.2599149
%0 Conference Paper
%B IEEE Workshop on Statistical Signal Processing (SSP)
%D 2016
%T Design of data-injection adversarial attacks against spatial field detectors
%A R. López-Valcarce
%A Daniel Romero
%K adversarial signal processing
%K compass
%K wsn
%X Data-injection attacks on spatial field detection corrupt a subset of measurements to cause erroneous decisions. We consider a centralized decision scheme exploiting spatial field smoothness to overcome lack of knowledge on system parameters such as noise variance. We obtain closed-form expressions for system performance and investigate strategies for an intruder injecting false data in a fraction of the sensors in order to reduce the probability of detection. The problem of determining the most vulnerable subset of sensors is also analyzed.

%B IEEE Workshop on Statistical Signal Processing (SSP) %C Palma de Mallorca, Spain %8 06/2016 %G eng %0 Journal Article %J IEEE/ACM Transactions on Networking %D 2016 %T Design of pool mixes against profiling attacks in real conditions %A Simon Oya %A Fernando Pérez-González %A Carmela Troncoso %K adversarial signal processing %K compass %B IEEE/ACM Transactions on Networking %V 24 %P 3662-3675 %8 12/2016 %G eng %N 6 %R 10.1109/TNET.2016.2547391 %0 Journal Article %J IEEE Transactions on Signal Processing %D 2016 %T Designing incoherent frames through convex techniques for optimized compressed sensing %A Cristian Rusu %A Nuria González-Prelcic %K compass %K compressed sensing %B IEEE Transactions on Signal Processing %V 64 %P 2334-2344 %8 May/2016 %G eng %N 9 %& 2334 %0 Thesis %D 2016 %T Detection of Image Resampling and Video Encoding Footprints for Forensic Applications %A David Vázquez-Padín %I University of Vigo %C Vigo %8 01/2016 %G eng %0 Conference Paper %B IEEE Workshop on Statistical Signal Processing (SSP) %D 2016 %T Distributed multivariate regression with unknown noise covariance in the presence of outliers: a minimum description length approach %A R. López-Valcarce %A Daniel Romero %A Josep Sala %A Alba Pagès-Zamora %K compass %K wsn %XWe consider the problem of estimating the coefficients in a multivariable linear model by means of a wireless sensor network

which may be affected by anomalous measurements. The noise covariance matrices at the different sensors are assumed

unknown. Treating outlying samples, and their support, as additional nuisance parameters, the Maximum Likelihood

estimate is investigated, with the number of outliers being estimated according to the Minimum Description Length

principle. A distributed implementation based on iterative consensus techniques is then proposed, and it is shown effective

for managing outliers in the data.

%B IEEE Workshop on Statistical Signal Processing (SSP)
%C Palma de Mallorca, Spain
%G eng
%0 Conference Paper
%B ACM Workshop on Information Hiding and Multimedia Security
%D 2016
%T Dynamic Privacy-Preserving Genomic Susceptibility Testing
%A Mina Namazi
%A Juan Ramón Troncoso-Pastoriza
%A Fernando Pérez-González
%B ACM Workshop on Information Hiding and Multimedia Security
%P 45-50
%8 06/2016
%G eng
%0 Conference Paper
%B Information Theory and Applications Workshop (ITA
%D 2016
%T Estimating millimeter wave channels using out-of-band measurements
%A Anum Ali
%A Nuria González-Prelcic
%A R.W. Heath Jr.
%K compass
%K mmWave
%B Information Theory and Applications Workshop (ITA
%8 January, 2016
%G eng
%0 Journal Article
%J IEEE Transactions on Signal Processing
%D 2016
%T Fast orthonormal sparsifying transforms based on Householder reflectors
%A C. Rusu
%A Nuria González-Prelcic
%A R.W. Heath Jr.
%K compass
%K compressed sensing
%B IEEE Transactions on Signal Processing
%V 64
%P 6589-6599
%8 12/2016
%G eng
%N 24
%R 10.1109/TSP.2016.2612168
%0 Conference Paper
%B IEEE International Conference on Image Processing (ICIP)
%D 2016
%T Fast Sequential Forensic Detection of Camera Fingerprint
%A Fernando Pérez-González
%A Miguel Masciopinto
%A Iria González-Iglesias
%A Pedro Comesaña
%B IEEE International Conference on Image Processing (ICIP)
%G eng
%0 Thesis
%D 2016
%T Flat Fading Channel Estimation Based on Dirty Paper Coding
%A Gabriel Domínguez-Conde
%I University of Vigo
%C Vigo
%G eng
%0 Conference Paper
%B ACM Workshop on Information Hiding and Multimedia Security
%D 2016
%T Forensics of high quality and nearly identical JPEG image recompression
%A Cecilia Pasquini
%A Pascal Schoettle
%A Rainer Bohme
%A Giulia Boato
%A Fernando Pérez-González
%B ACM Workshop on Information Hiding and Multimedia Security
%G eng
%0 Conference Paper
%B Asilomar Conf. on Signals, Systems and Computers
%D 2016
%T Frequency selective multiuser hybrid precoding for mmWave systems with imperfect channel knowledge
%A Jose P. Gonzalez-Coma
%A Nuria González-Prelcic
%A Luis Castedo
%A Robert W. Heath Jr.
%K compass
%K mmWave
%B Asilomar Conf. on Signals, Systems and Computers
%8 11/2016
%G eng
%R 10.1109/ACSSC.2016.7869044
%0 Conference Paper
%B 8th Advanced Satellite Multimedia Systems Conference and 14th Signal Processing for Space Communications Workshop
%D 2016
%T Full-duplex operation in two-way broadcast service for maritime applications
%A Tomás Ramírez
%A Carlos Mosquera
%K compass
%K full duplex
%K satcom
%B 8th Advanced Satellite Multimedia Systems Conference and 14th Signal Processing for Space Communications Workshop
%8 09/2016
%G eng
%0 Journal Article
%J IEEE Access
%D 2016
%T Hybrid MIMO Architectures for Millimeter Wave Communications: Phase Shifters or Switches?
%A Mendez-Rial, Roi
%A Rusu, Cristian
%A Nuria González-Prelcic
%A Alkhateeb, A.
%A Heath Jr, Robert W.
%B IEEE Access
%V 4
%P 247-267
%8 January, 2016
%G eng
%U http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7370753
%R 10.1109/ACCESS.2015.2514261
%0 Conference Paper
%B IEEE Global Telecommunications Conf. (GLOBECOM)
%D 2016
%T Hybrid precoders and combiners for mmWave MIMO systems with per-antenna power constraints
%A R. López-Valcarce
%A Nuria González-Prelcic
%A Cristian Rusu
%A R. W. Heath, Jr
%K compass
%K mmWave
%X This paper considers the design of hybrid precoders

and combiners for mmWave MIMO systems with per-antenna

power constraints and the additional limitations introduced by

the phase-shifting network in the analog processing stage. Previous

hybrid designs were obtained using a total power constraint,

but in practical implementations per-antenna constraints are

more realistic, specially at mmWave, given the large number of

power amplifiers used in the transmit array. Assuming perfect

channel knowledge, we obtain first an approximation to the alldigital

solution for the precoder and the combiner given the

per-antenna constraints. Then, we develop a new method for the

design of the hybrid precoder and combiner which attempts to

match such all-digital approximation. Simulation results show

the effectiveness of the proposed approach, which performs close

to the all-digital solution.

%B IEEE Global Telecommunications Conf. (GLOBECOM)
%G eng
%0 Conference Paper
%B IEEE International Workshop on Information Forensics and Security (WIFS)
%D 2016
%T Image denoising in the encrypted domain
%A Alberto Pedrouzo-Ulloa
%A Juan Ramón Troncoso-Pastoriza
%A Fernando Pérez-González
%K compass
%K homomorphic processing
%K Image Denoising
%K Image Encryption
%K lattice cryptography
%B IEEE International Workshop on Information Forensics and Security (WIFS)
%I IEEE
%C Abu Dhabi, UAE
%8 12/2016
%G eng
%0 Conference Paper
%B 8th Advanced Satellite Multimedia Systems Conference 14th Signal Processing for Space Communications Workshop
%D 2016
%T The impact of feeder link interference in multiple gateway multibeam satellite systems
%A Vahid Joroughi
%A Carlos Mosquera
%K compass
%K satcom
%B 8th Advanced Satellite Multimedia Systems Conference 14th Signal Processing for Space Communications Workshop
%8 09/2016
%G eng
%0 Conference Paper
%B 8th Advanced Satellite Multimedia Systems Conference and 14th Signal Processing for Space Communications Workshop
%D 2016
%T Link adaptation in mobile satellite links: field trials results
%A Anxo Tato
%A Carlos Mosquera
%A Iago Gómez
%K compass
%K satcom
%B 8th Advanced Satellite Multimedia Systems Conference and 14th Signal Processing for Space Communications Workshop
%8 09/2016
%G eng
%0 Journal Article
%J International Journal of Satellite Communications and Networking
%D 2016
%T Link adaptation in mobile satellite links: schemes for different degrees of CSI knowledge
%A Alberto Rico-Alvariño
%A Jesus Arnau
%A Carlos Mosquera
%K compass
%K satcom
%B International Journal of Satellite Communications and Networking
%V 34
%P 679-694
%8 09/2016
%G eng
%N 5
%0 Journal Article
%J IEEE Trans. Wireless Communications
%D 2016
%T Low complexity hybrid precoding strategies for millimeter wave communication systems
%A Cristian Rusu
%A Roi Méndez-Rial
%A Nuria González-Prelcic
%A Robert W. Heath Jr.
%K compass
%K mmWave
%X Millimeter communication systems use large antenna arrays to provide good average received power and to take advantage of multi-stream MIMO communication. Unfortunately, due to power consumption in the analog front-end, it is impractical to perform beamforming and fully digital precoding at baseband. Hybrid precoding/combining architectures have been proposed to overcome this limitation. The hybrid structure splits the MIMO processing between the digital and analog domains, while keeping the performance close to that of the fully digital solution. In this paper, we introduce and analyze several algorithms that efficiently design hybrid precoders and combiners starting from the known optimum digital precoder/combiner, which can be computed when perfect channel state information is available. We propose several low complexity solutions which provide different trade-offs between performance and complexity. We show that the proposed iterative solutions perform better in terms of spectral efficiency and/or are faster than previous methods in the literature. All of them provide designs which perform close to the known optimal digital solution. Finally, we study the effects of quantizing the analog component of the hybrid design and show that even with coarse quantization, the average rate performance is good.

%B IEEE Trans. Wireless Communications %V 15 %P 8380 - 8393 %8 12/2016 %G eng %N 12 %R 10.1109/TWC.2016.2614495 %0 Journal Article %J IEEE Transactions on Signal Processing %D 2016 %T Multiantenna GLR detection of rank-one signals with known power spectral shape under spatially uncorrelated noise %A Josep Sala %A Gonzalo Vázquez-Vilar %A R. López-Valcarce %A Saeid Sedighi %A Abbas Taherpour %K cognitive radio %K compass %XWe establish the generalized likelihood ratio (GLR) test for a Gaussian signal of known power spectral shape and unknown rank-one spatial signature in additive white Gaussian noise with an unknown diagonal spatial correlation matrix. This is motivated by spectrum sensing problems in dynamic spectrum access (DSA), in which the temporal correlation of the primary signal can be assumed known up to a scaling, and where the noise is due to an uncalibrated receive array. For spatially independent identically distributed (i.i.d.) noise, the corresponding GLR test reduces to a scalar optimization problem, whereas the GLR detector in the general non-i.i.d. case yields a more involved expression, which can be computed via alternating optimization methods. Low signal-to-noise ratio (SNR) approximations to the detectors are given, together with an asymptotic analysis showing the influence on detection performance of the signal power spectrum and SNR distribution across antennas. Under spatial rank-P conditions, we show that the rank-one GLR detectors are consistent with a statistical criterion that maximizes the output energy of a beamformer operating on filtered data. Simulation results support our theoretical findings in that exploiting prior knowledge on the signal power spectrum can result in significant performance improvement.

%B IEEE Transactions on Signal Processing %V 64 %P 6269-6283 %8 12/2016 %G eng %N 23 %& 6269 %R 10.1109/TSP.2016.2601290 %0 Conference Paper %B European Signal Processing Conference (EUSIPCO) %D 2016 %T Online EM-based distributed estimation in sensor networks with faulty nodes %A Pere Gimenez-Febrer %A Alba Pagès-Zamora %A R. López-Valcarce %K compass %K wsn %XThis paper focuses on the problem of the distributed estimation of a parameter vector based on noisy observations regularly acquired by the nodes of a wireless sensor network and assuming that some of the nodes have faulty sensors. We propose two online schemes, both centralized and distributed, based on the Expectation-Maximization (EM) algorithm. These algorithms are able to identify and disregard the faulty nodes, and provide a refined estimate of the parameters each time instant after a new set of observations is acquired. Simulation results demonstrate that the centralized versions of the proposed online algorithms attain the same estimation error as the centralized batch EM, whereas the distributed versions come very close to matching the batch EM.

%B European Signal Processing Conference (EUSIPCO)
%C Budapest, Hungary
%8 09/2016
%G eng
%0 Journal Article
%J IEEE J. Selected Topics in Signal Processing. Special issue on Signal Processing for Millimeter Wave Wireless Communications
%D 2016
%T An overview of signal processing techniques for millimeter wave MIMO systems
%A Robert W. Heath Jr.
%A Nuria González-Prelcic
%A Sundeep Rangan
%A Wonil Roh
%A Akbar M. Sayeed
%K compass
%K mmWave
%X Communication at millimeter wave (mmWave) frequencies is defining a new era of wireless communication. The mmWave band offers higher bandwidth communication channels versus those presently used in commercial wireless systems. The applications of mmWave are immense: wireless local and personal area networks in the unlicensed band, 5G cellular systems, not to mention vehicular area networks, ad hoc networks, and wearables. Signal processing is critical for enabling the next generation of mmWave communication. Due to the use of large antenna arrays at the transmitter and receiver, combined with radio frequency and mixed signal power constraints, new multiple-input multiple-output (MIMO) communication signal processing techniques are needed. Because of the wide bandwidths, low complexity transceiver algorithms become important. There are opportunities to exploit techniques like compressed sensing for channel estimation and beamforming. This article provides an overview of signal processing challenges in mmWave wireless systems, with an emphasis on those faced by using MIMO communication at higher carrier frequencies.

%B IEEE J. Selected Topics in Signal Processing. Special issue on Signal Processing for Millimeter Wave Wireless Communications %V 10 %P 436 - 453 %8 04/2016 %G eng %N 3 %R 10.1109/JSTSP.2016.2523924 %0 Journal Article %J Linear Algebra and its Applications %D 2016 %T Properties of real and complex ETFs and their application to the design of low coherence frames %A Cristian Rusu %A Nuria González-Prelcic %A Robert W. Heath Jr. %B Linear Algebra and its Applications %V 508 %P 81-90 %8 November, 2016 %G eng %U http://www.sciencedirect.com/science/article/pii/S0024379516302555 %0 Conference Paper %B Information Theory and Applications Workshop (ITA %D 2016 %T Radar aided mmWave beam alignment in V2I communications supporting antenna diversity %A Nuria González-Prelcic %A R. Méndez-Rial %A R.W. Heath Jr. %K compass %K mmWave %B Information Theory and Applications Workshop (ITA %8 January, 2016 %G eng %0 Journal Article %J IEEE Trans. Communications %D 2016 %T Robust analog precoding designs for millimeter wave MIMO transceivers with frequency and time division duplexing %A Pengfei Xia %A Robert W. Heath Jr. %A Nuria González-Prelcic %K compass %K mmWave %XMillimeter wave (mmWave) communication provides high data rates thanks to large arrays at the transmitter and receiver, coupled with large bandwidth channels. Exploiting the arrays is challenging due to the need to configure precoding at the transmitter based on the large frequency selective channel. In this paper, we exploit the power iteration principle and propose a robust analog precoding training algorithm that can be applied in both frequency division duplex transmission systems and time division duplex transmission systems with or without RF calibration. We further analyze the convergence of the proposed algorithm and show how it converges to the singular value decomposition optimality exponentially. We propose null space projection on top of the power iteration to form multiple orthogonal beams at the transmitter and receiver. Strongest tap selection with proper energy pruning is used to collect as much precoding gain as possible from a frequency selective fading channel. The exponential effective SINR mapping performance is evaluated and demonstrates that the overall approach works smoothly. Numerical simulation results demonstrate algorithm robustness and the algorithm works not only for the simplified mmWave directional channels, but also for more general rich scattering channels.

%B IEEE Trans. Communications %V 64 %P 4622 - 4634 %8 11/2016 %G eng %N 11 %R 10.1109/TCOMM.2016.2604312 %0 Conference Paper %B 20th International ITG Workshop on Smart Antennas (WSA) %D 2016 %T Robust analog precoding designs for millimeter wave MIMO transceivers %A Pengfei Xia %A Robert Heath %A Nuria González-Prelcic %K compass %K mmWave %B 20th International ITG Workshop on Smart Antennas (WSA) %8 March, 2016 %G eng %0 Journal Article %J Microwave Journal %D 2016 %T Security in automotive radar and vehicular networks %A E. R. Yeh %A J. Choi %A Nuria González-Prelcic %A C. Bhat %A R. W. Heath Jr. %K compass %K mmWave %B Microwave Journal %G eng %0 Report %D 2016 %T Technical Report for ID TNET-2015-00294 “Optimal delay characteristic when the number of users is comparable to the number of rounds" %A Simon Oya %A Fernando Pérez-González %A Carmela Troncoso %G eng %0 Report %D 2016 %T Technical Report TSC/SO/24082016: Filter design for delay-based anonymous communications %A Simon Oya %A Fernando Pérez-González %A Carmela Troncoso %G eng %0 Conference Paper %B IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP) %D 2016 %T The use of unit norm tight measurement matrices for one-bit compressed sensing %A C. Rusu %A Nuria González-Prelcic %A R. W. Heath Jr. %K compass %K compressed sensing %XIn this paper we analyze the mean squared error (MSE) for one-bit compressed sensing schemes based on measurement matrices that correspond to unit norm tight frames. We show that, as in the unquantized case, sensing with unit norm tight frames improves the MSE in the reconstruction of sparse vectors from one-bit measurements using l1 and thresholding algorithms. From our analytical and experimental results we conclude that when implementing one-bit compressed sensing schemes with fixed measurement matrices unit norm tight frames are the measurements of choice

%B IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP) %8 2016 %G eng %0 Conference Paper %B IEEE WoWMoM 2016 Workshop on Fifth Generation Wireless %D 2016 %T Wideband self-interference cancellation for better spectrum use %A Carlos Mosquera %K adaptive signal processing %K compass %K full duplex %B IEEE WoWMoM 2016 Workshop on Fifth Generation Wireless %8 06/2016 %G eng %0 Conference Paper %B IEEE International Workshop on Computational Advances in Multi-Sensor Adaptive Processing (CAMSAP) %D 2015 %T Adaptive hybrid precoding and combining in mmWave multiuser MIMO systems based on compressed covariance estimation %A R. Méndez-Rial %A Nuria González-Prelcic %A R. W. Heath Jr. %K compass %K mmWave %B IEEE International Workshop on Computational Advances in Multi-Sensor Adaptive Processing (CAMSAP) %8 December, 2015 %G eng %0 Conference Paper %B IEEE Global Telecommunications Conf. (GLOBECOM), %D 2015 %T Adaptive one-bit compressive sensing with application to low-precision receivers at mmWave %A C. Rusu %A R. Méndez-Rial %A Nuria González-Prelcic %A R. W. Heath, Jr %K compass %K mmWave %B IEEE Global Telecommunications Conf. (GLOBECOM), %8 December, 2015 %G eng %0 Conference Paper %B European Signal Processing Conf. (EUSIPCO) %D 2015 %T Attack detectors for data aggregation in clustered sensor networks %A R. López-Valcarce %A Daniel Romero %K adversarial signal processing %K compass %K wsn %XAmong many security threats to sensor networks, compromised sensing is particularly challenging due to the fact that it cannot be addressed by standard authentication approaches. We consider a clustered scenario for data aggregation in which an attacker injects a disturbance in sensor readings. Casting the problem in an estimation framework, we systematically apply the Generalized Likelihood Ratio approach to derive attack detectors. The analysis under different attacks reveals that detectors based on similarity of means across

clusters are suboptimal, with Bartlett’s test for homoscedasticity constituting a good candidate when lacking a priori knowledge of the variance of the underlying distribution.

%B European Signal Processing Conf. (EUSIPCO)
%I EURASIP
%C Nice, France
%P 2098-2102
%8 accepted
%G eng
%0 Conference Paper
%B IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP)
%D 2015
%T An attack on antenna subset modulation for millimeter-wave communication
%A Cristian Rusu
%A Nuria González-Prelcic
%A Robert W. Heath Jr.
%K adversarial signal processing
%K compass
%K mmWave
%X Antenna subset modulation (ASM) is a physical layer security technique that is well suited for millimeter wave communication systems. The key idea is to vary the radiation pattern at the symbol rate by selecting one from a subset of patterns with a similar main lobe and different side lobes. This paper shows that ASM is not robust to an eavesdropper that makes multiple simultaneous measurements at multiple angles. The measurements are combined and used to formulate an estimation problem to undo the effects of the side lobe randomization. Simulations show the performance of the estimation algorithms and how the eavesdropper can effectively recover the information if the signal-to-noise ratio exceeds a certain threshold. Using fewer active radio frequency chains makes it harder for the attacker to recover the transmit symbol, at the expense of more grating lobes.

%B IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP) %I IEEE %C Brisbane, Australia %P 2914-2918 %8 04/2015 %G eng %0 Conference Paper %B IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP) %D 2015 %T Augmented covariance estimation with a cyclic approach in DOA %A Roi Méndez-Rial %A Nuria González-Prelcic %A Robert W. Heath Jr. %K DOA estimation %K Non-uniformly spaced arrays %XHigh resolution direction-of-arrival (DOA) estimation is an important problem in many array signal processing applications. This paper proposes an augmented covariance estimator for DOA estimation. The new method exploits the periodicity of the covariance lags when the DOAs are assumed on a discrete grid with a certain resolution. Then, it achieves twice the resolution of typical methods such as the direct augmentable approach or forward backward spatial smoothing. When the sources are not on the discrete grid, an interpolated array manifold technique is proposed to mitigate the grid mismatch error.

%B IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP) %I IEEE %C Brisbane, Australia %P 2784-2788 %8 04/2015 %G eng %0 Conference Paper %B IEEE International Conference on Communications (ICC) %D 2015 %T Blind Satellite Inter-Gateway Interference Mitigation %A J. Arnau %A C. Mosquera %K compass %K satcom %B IEEE International Conference on Communications (ICC) %8 2015 %G eng %0 Journal Article %J IEEE Trans. Information Theory %D 2015 %T Compression Limits for Random Vectors with Linearly Parameterized Second-Order Statistics %A Daniel Romero %A R. López-Valcarce %A Geert Leus %K compass %K compressed sensing %XThe class of complex random vectors whose covariance

matrix is linearly parameterized by a basis of Hermitian

Toeplitz (HT) matrices is considered, and the maximum

compression ratios that preserve all second-order information

are derived — the statistics of the uncompressed vector must

be recoverable from a set of linearly compressed observations.

This kind of vectors arises naturally when sampling widesense

stationary random processes and features a number of

applications in signal and array processing.

Explicit guidelines to design optimal and nearly optimal

schemes operating both in a periodic and non-periodic fashion

are provided by considering two of the most common linear

compression schemes, which we classify as dense or sparse. It

is seen that the maximum compression ratios depend on the

structure of the HT subspace containing the covariance matrix of

the uncompressed observations. Compression patterns attaining

these maximum ratios are found for the case without structure as

well as for the cases with circulant or banded structure. Universal

samplers are also proposed to compress unknown HT subspaces.

%B IEEE Trans. Information Theory
%V 61
%P 1410-1425
%8 03/2015
%G eng
%N 3
%& 1410
%R 10.1109/TIT.2015.2394784
%0 Journal Article
%J IEEE Trans. Signal Processing
%D 2015
%T Cramér-Rao Bounds for SNR Estimation of Oversampled Linearly Modulated Signals
%A R. López-Valcarce
%A J. Villares
%A J. Riba
%A W. Gappmair
%A C. Mosquera
%K adaptive signal processing
%K compass
%K Cramér-Rao bound (CRB)
%K dynacs
%K oversampling
%K Signal-to-noise ratio (SNR)
%X Most Signal-to-noise ratio (SNR) estimators use the

receiver matched filter output sampled at the symbol rate, an

approach which does not preserve all information in the analog

waveform due to aliasing. Thus, it is relevant to ask whether

avoiding aliasing could improve SNR estimation. To this end, we

compute the corresponding data-aided (DA) and non-data-aided

(NDA) Cramér-Rao bounds (CRBs). We adopt a novel dual filter

framework, which is shown to be information-preserving under

suitable conditions and considerably simplifies the analysis. It is

shown that the CRB can be substantially reduced by exploiting

any available excess bandwidth, depending on the modulation

scheme, the SNR range, and the estimator (DA or NDA) type.

%B IEEE Trans. Signal Processing
%V 63
%P 1675-1683
%8 04/2015
%G eng
%N 7
%& 1675
%R 10.1109/TSP.2015.2396013
%0 Conference Paper
%B IEEE Int. Workshop on Signal Processing Advances in Wireless Communications (SPAWC)
%D 2015
%T Dictionary-free Hybrid Precoders and Combiners for mmWave MIMO Systems
%A Roi Méndez-Rial
%A Cristian Rusu
%A Nuria González-Prelcic
%A Robert W. Heath Jr.
%K compass
%K mmWave
%B IEEE Int. Workshop on Signal Processing Advances in Wireless Communications (SPAWC)
%I IEEE
%C Stockholm, Sweden
%8 06/2015
%G eng
%0 Conference Paper
%B IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP)
%D 2015
%T Distributed AoA-based Source Positioning in NLOS with Sensor Networks
%A Pere Gimenez-Febrer
%A Alba Pagès-Zamora
%A Silvana Silva Pereira
%A R. López-Valcarce
%K compass
%K wsn
%X This paper focuses on the problem of positioning a source using angle-of-arrival measurements taken by a wireless sensor network in which some of the nodes experience non-line-of-sight (NLOS) propagation conditions. In order to mitigate the errors induced by the nodes in NLOS, we derive an algorithm that combines the expectation-maximization algorithm with a weighted least-squares estimation of the source position so that the nodes in NLOS are eventually identified and discarded. Moreover, a distributed version of this algorithm based on a diffusion strategy that iteratively refines the position estimate while driving the network to a consensus is presented.

%B IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP)
%I IEEE
%C Brisbane, Australia
%8 04/2015
%G eng
%0 Conference Paper
%B IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP)
%D 2015
%T Distributed TLS Estimation under Random Data Faults
%A Silvana Silva Pereira
%A Alba Pagès-Zamora
%A R. López-Valcarce
%K compass
%K wsn
%X This paper addresses the problem of distributed estimation of a parameter vector in the presence of noisy input and output data as well as data faults, performed by a wireless sensor network in which only local interactions among the nodes are allowed. In the presence of unreliable observations, standard estimators become biased and perform poorly in low signal-to-noise ratios. We propose two different distributed approaches based on the Expectation-Maximization algorithm: in the first one the regressors are estimated at each iteration,

whereas the second one does not require explicit regressor estimation. Numerical results show that the proposed methods approach the performance of a clairvoyant scheme with knowledge of the random data faults.

%B IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP)
%I IEEE
%C Brisbane, Australia
%8 04/2015
%G eng
%0 Thesis
%D 2015
%T Estimation, Detection, and Learning for Dynamic Spectrum Access
%A Daniel Romero
%K cognitive radio
%K compass
%K dynacs
%K wsn
%I University of Vigo
%C Vigo, Spain
%V Ph.D.
%8 05/2015
%G eng
%9 Ph.D. Thesis
%0 Journal Article
%J IEEE Transactions on Information Forensics and Security
%D 2015
%T Forensic detection of processing operator chains: recovering the history of filtered JPEG images
%A Valentina Conotter
%A Pedro Comesaña
%A Fernando Pérez-González
%K compass
%K forensics
%B IEEE Transactions on Information Forensics and Security
%G eng
%1 Accepted for publication.

%R 10.1109/TIFS.2015.2424195 %0 Conference Paper %B IEEE International Conference on Communications (ICC) %D 2015 %T Frequency Reuse in Dual Satellite Settings: an Initial Evaluation of Full Duplex Operation %A D. Martiñán-Otero %A C. Mosquera %K compass %K full duplex %K satcom %B IEEE International Conference on Communications (ICC) %G eng %0 Journal Article %J Information Processing Letters %D 2015 %T A Greedy Topology Design to Accelerate Consensus in Broadcast Wireless Sensor Networks %A Massimo Vecchio %A R. López-Valcarce %K compass %K wsn %XWe present techniques to improve convergence speed of distributed average consensus algorithms in wireless sensor networks by means of topology design. A broadcast network is assumed, so that only the transmit power of each node can be independently controlled, rather than each individual link. Starting with a maximally connected configuration in which all nodes transmit at full power, the proposed methods successively reduce the transmit power of a chosen node in order to remove one and only one link; nodes are greedily selected either in order to yield fastest convergence at each step, or if they have the largest degree in the network. These greedy schemes provide a good complexity-performance tradeoff with respect to full-blown global search methods. As a side benefit, improving the convergence speed also results in savings in energy consumption with respect to the maximally connected setting.

%B Information Processing Letters %V 115 %P 408-413 %8 03/2015 %G eng %N 3 %& 408 %R 10.1016/j.ipl.2014.11.009 %0 Journal Article %J Journal of Network and Computer Applications %D 2015 %T Improving Area Coverage of Wireless Sensor Networks Via Controllable Mobile Nodes: a Greedy Approach %A Massimo Vecchio %A R. López-Valcarce %K compass %K wsn %XReliable wide-area monitoring with Wireless Sensor Networks (WSNs) remains a problem of

interest: simply deploying more nodes to cover wider areas is generally not a viable solution, due to

deployment and maintenance costs and the increase in radio interference. One possible solution

gaining popularity is based on the use of a reduced number of mobile nodes with controllable

trajectories in the monitored field. In this framework, we present a distributed technique for iteratively

computing the trajectories of the mobile nodes in a greedy fashion. The static sensor nodes actively

assist the mobile nodes in this task by means of a bidding protocol, thus participating towards the goal

of maximizing the area coverage of the monitored field. The performance of the proposed technique is

evaluated on various simulation scenarios with different number of mobile and static nodes in terms of

achieved coverage and mean time to achieve X% coverage. Comparison with previous state-of-the-art

techniques reveals the effectiveness and stability of the proposed method.

%B Journal of Network and Computer Applications
%V 48
%P 1-13
%8 02/2015
%G eng
%R 10.1016/j.jnca.2014.10.007
%0 Conference Paper
%B IEEE Int. Conference on Communications (ICC)
%D 2015
%T Low Complexity Hybrid Sparse Precoding and Combining in Millimeter Wave MIMO Systems
%A Cristian Rusu
%A Roi Méndez-Rial
%A Nuria González-Prelcic
%A Robert W. Heath Jr.
%K compass
%K mmWave
%B IEEE Int. Conference on Communications (ICC)
%I IEEE
%C London, UK
%8 06/2015
%G eng
%0 Conference Paper
%B Asilomar Conf. on Signals, Systems, and Computers
%D 2015
%T Low Resolution Adaptive Compressed Sensing for mmWave MIMO receivers
%A C. Rusu
%A Nuria González-Prelcic
%A R.W. Heath Jr.
%K compass
%K mmWave
%B Asilomar Conf. on Signals, Systems, and Computers
%8 November, 2015
%G eng
%0 Book Section
%B Cooperative and Cognitive Satellite Systems
%D 2015
%T Multibeam Joint Detection
%A J. Arnau
%A R. de Lamare
%A C. Mosquera
%K satcom
%B Cooperative and Cognitive Satellite Systems
%I Elsevier
%G eng
%0 Conference Paper
%B IEEE 9th International Symposium on Intelligent Signal Processing (WISP)
%D 2015
%T Multipath cancellation in broadband acoustic local positioning systems
%A Fernando J. Alvarez
%A R. López-Valcarce
%K compass
%K wsn
%X This work proposes a novel method to estimate the Line-of-Sight Time-of-Flights (LOS-TOFs) in a broadband acoustic local positioning system (ALPS) with strong multipath interference. The proposed method is based on the Matching Pursuit channel estimation algorithm that provides a low complexity approximation to the Maximum Likelihood solution for sparse channels. A multichannel version of this algorithm has been implemented to estimate a minimum of three coefficients in the channel responses of a particular ALPS, composed of four beacons that perform the simultaneous emission of BPSK modulated 255-bit Kasami codes. A statistical analysis of performance has been carried out by using a set of test signals synthetically generated to simulate different positions and reflection coefficients of the environment. The results of this analysis show the enhanced capability of the proposed method to estimate the LOS-TOFs under strong multipath interference, with respect to that of a classical system based on correlation + thresholding.

%B IEEE 9th International Symposium on Intelligent Signal Processing (WISP) %I IEEE %C Siena, Italy %8 05/2015 %G eng %R 10.1109/WISP.2015.7139174 %0 Conference Paper %B IEEE International Conference on Acoustics, Speech and Signal Processing %D 2015 %T Multivariate Lattices for Encrypted Image Processing %A Alberto Pedrouzo-Ulloa %A Juan Ramón Troncoso-Pastoriza %A Fernando Pérez-González %K homomorphic encryption %K lattice cryptography %K SPED %B IEEE International Conference on Acoustics, Speech and Signal Processing %I IEEE %C Brisbane, Australia %8 04/2015 %G eng %0 Conference Paper %B Twelfth International Symposium on Wireless Communication Systems (ISWCS) %D 2015 %T Pushing for higher rates and efficiency in Satcom: the different perspectives within SatNExIV %A Miguel Ángel Vázquez %A Ana Pérez Neira %A Carlos Mosquera %A Bhavani Shankar %A Pol Henarejos %A Athanasios Panagopoulos %A Giovanni Giambene %A Vasilios Siris %A George Polyzos %A Nader Alagha %K satcom %B Twelfth International Symposium on Wireless Communication Systems (ISWCS) %C Brussels %G eng %0 Conference Paper %B IEEE International Workshop on Signal Processing Advances in Wireless Communications, SPAWC %D 2015 %T Robust Adaptive Coding and Modulation Scheme for the Mobile Satellite Forward Link %A Alberto Rico-Alvariño %A Anxo Tato %A Carlos Mosquera %K compass %K satcom %B IEEE International Workshop on Signal Processing Advances in Wireless Communications, SPAWC %G eng %0 Conference Paper %B IEEE Int. Conference on Acoustics, Speech and Signal Processing (ICASSP) %D 2015 %T Spectrum Cartography using quantized observations %A Daniel Romero %A Seung-Jun Kim %A R. López-Valcarce %A Georgios Giannakis %K cognitive radio %K compass %K compressed sensing %K spectrum sensing %XThis work proposes a spectrum cartography algorithm used for learning the power spectrum distribution over a wide frequency band across a given geographic area. Motivated by low-complexity sensing hardware and stringent communication constraints, compressed and quantized measurements are considered. Setting out from a nonparametric regression framework, it is shown that a sensible approach leads to a support vector machine formulation. The simulated tests verify that accurate spectrum maps can be constructed using a simple sensing architecture with significant savings in the feedback.

%B IEEE Int. Conference on Acoustics, Speech and Signal Processing (ICASSP)
%I IEEE
%C Brisbane, Australia
%8 04/2015
%G eng
%0 Conference Paper
%B IEEE 16th Int. Workshop on Signal Processing Advances in Wireless Communications (SPAWC)
%D 2015
%T Subspace-constrained SINR optimization in MIMO full-duplex relays under limited dynamic range
%A Emilio Antonio-Rodríguez
%A R. López-Valcarce
%A Taneli Riihonen
%A Stefan Werner
%A Risto Wichman
%K adaptive signal processing
%K compass
%K full duplex
%X We propose a method for maximizing the signal-to-interference-plus-noise ratio (SINR) in a wideband full-duplex MIMO regenerative relay that accounts limited dynamic range of the receiver and transmitter impairments. Transmit and receive filters are designed at the relay, by means of an alternating minimization algorithm, to minimize the interference at the decoder input in the destination node. We impose channel shortening and subspace constraints to ensure that the received signal at the destination is not compromised. Simulation results show that the presented method significantly outperforms other constrained approaches.

%B IEEE 16th Int. Workshop on Signal Processing Advances in Wireless Communications (SPAWC)
%I IEEE
%C Stockholm, Sweden
%8 06/2015
%G eng
%0 Conference Paper
%B EUSIPCO
%D 2015
%T An SVD Approach to Forensic Image Resampling Detection
%A David Vázquez-Padín
%A Pedro Comesaña
%A Fernando Pérez-González
%K compass
%K digital image forensics
%K resampling detection
%K SVD
%K tampering detection
%X This paper describes a new strategy for image resampling detection whenever the applied resampling factor is larger than one. Delving into the linear dependencies induced in an image after the application of an upsampling operation, we show that interpolated images belong to a subspace defined by the interpolation kernel. Within this framework, by computing the SVD of a given image block and a measure of its degree of saturated pixels per row/column, we derive a simple detector capable of discriminating between upsampled images and genuine images. Furthermore, the proposed detector shows remarkable results with blocks of small size and outperforms state-of-the-art methods.

%B EUSIPCO
%P 2112-2116
%8 09/2015
%G eng
%0 Journal Article
%J IEEE Communications Letters
%D 2014
%T Active Interference Cancellation for OFDM Spectrum Sculpting: Linear Processing is Optimal
%A Schmidt, J.F.
%A Daniel Romero
%A R. López-Valcarce
%K cognitive radio
%K compass
%K dynacs
%K spectrum shaping
%X Active interference cancellation (AIC) is a multicarrier spectrum sculpting technique which reduces the power of undesired out-of-band emissions by adequately modulating a subset of reserved cancellation subcarriers. In most schemes online complexity is a concern, and thus cancellation subcarriers have traditionally been constrained to linear combinations of the data subcarriers. Recent AIC designs truly minimizing out-of-band emission shift complexity to the offline design stage, motivating the consideration of more general mappings to improve performance. We show that there is no loss in optimality incurred by constraining these mappings to the set of linear functions.

%B IEEE Communications Letters %V 18 %P 1543-1546 %8 09/2014 %G eng %N 9 %& 1543 %R 10.1109/LCOMM.2014.2338316 %0 Conference Paper %B IEEE Sensor Array and Multichannel Signal Processing Workshop (SAM) %D 2014 %T Antenna competition to boost Active Interference Cancellation in cognitive MIMO-OFDM %A Schmidt, J.F. %A R. López-Valcarce %K cognitive radio %K dynacs %K spectrum shaping %X Active Interference Cancellation (AIC) techniques for OFDM spectrum sculpting have gained interest over the last years, and several extensions to the MIMO case have been recently proposed. However, these designs do not fully exploit the spatial diversity provided by the multiple transmit antennas, as canceler allocation is fixed. This paper proposes a more general mechanism for the allocation of the cancellation subcarriers across antennas in order to better exploit spatial diversity. In particular, we present a novel AIC design for cognitive MIMOOFDM systems, in which transmit antennas compete against each other for a fixed number of cancellation subcarriers. We show that this more general allocation approach results in significant performance improvements with respect to previous designs. %B IEEE Sensor Array and Multichannel Signal Processing Workshop (SAM) %C A Coruña, Spain %G eng %R 10.1109/SAM.2014.6882392 %0 Conference Paper %B Media Watermarking, Security, and Forensics %D 2014 %T Are you threatening me? Towards smart detectors in watermarking %A Mauro Barni %A Pedro Comesaña %A Fernando Pérez-González %A Benedetta Tondi %K adversarial signal processing %K watermarking %B Media Watermarking, Security, and Forensics %I SPIE %C San Francisco, CA, USA %8 02/2014 %G eng %R 10.1117/12.2036415 %0 Conference Paper %B Proc. ASMS & SPSC %D 2014 %T Balancing Closed and Open Loop CSI in Mobile Satellite Link Adaptation %A Alberto Rico-Alvariño %A Arnau, Jesus %A Carlos Mosquera %K dynacs %K satcom %B Proc. ASMS & SPSC %C Livorno, Italy %G eng %1

**Best paper award**

The Proportional Fair Scheduler (PFS) has become

a popular channel-aware resource allocation method in wireless

networks, as it effectively exploits multiuser diversity while

providing fairness to users. PFS decisions on which mobile station

(MS) to schedule next are based on Channel Quality Indicator

(CQI) values. Since CQI values are reported by the MSs to the

scheduler, network performance can be severely degraded if some

malicious MSs report forged information. Previous approaches to

this security issue are based either on modifying PFS, which may

be undesirable in some contexts, or authenticating CQI reports

by periodic transmission of challenges, which increases overhead.

Instead, we propose to detect misreporting attackers, based on the

time correlation features of the wireless channel. Our approach

does not require scheduler modification, and it does not increase

overhead. Simulation results under realistic settings are provided

to show the effectiveness of the proposed test.

%B IEEE Workshop on Information Forensics and Security (WIFS)
%C Atlanta, USA
%8 12/2014
%G eng
%R 10.1109/WIFS.2014.7084310
%0 Conference Paper
%B European Wireless 2014 (EW2014)
%D 2014
%T Dissection of multibeam satellite communications with a large-scale antenna system toolbox
%A Arnau, Jesus
%A Carlos Mosquera
%K dynacs
%K large-scale analysis
%K Massive MIMO
%K multibeam satellites
%K Multiuser detection
%K satcom
%X Current multibeam satellite systems consist of a very large number of spot beams. In this paper, we analyze them from the large scale MIMO perspective, and establish a comparison with massive MIMO systems. It will be shown that the large number of beams has important operational implications, and that it simplifies the analysis because it allows using asymptotic results. However, it will also be shown that multibeam satellite systems cannot be considered massive MIMO systems.

%B European Wireless 2014 (EW2014) %C Barcelona, Spain %P 548-553 %G eng %R ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6843099 %0 Conference Paper %B IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP) %D 2014 %T Distributed Total Least Squares Estimation over Networks %A R. López-Valcarce %A Silvana Silva Pereira %A Alba Pagès-Zamora %K dynacs %K wsn %XWe consider Total Least Squares (TLS) estimation in a network in which each node has access to a subset of equations of an overdetermined linear system. Previous distributed approaches require that the number of equations at each node be larger than the dimension L of the unknown parameter. We present novel distributed TLS estimators which can handle as few as a single equation per node. In the first scheme, the network computes an extended correlation matrix via standard iterative average consensus techniques, and the TLS estimate is extracted afterwards by means of an eigenvalue decomposition (EVD). The second scheme is EVD-free, but requires that a linear system of size L be solved at each iteration by each node. Replacing this step by a single Gauss-Seidel subiteration is shown to be an effective means to reduce computational cost without sacrificing performance.

%B IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP) %C Florence, Italy %G eng %R 10.1109/ICASSP.2014.6855074 %0 Conference Paper %B Privacy Enhancing Technologies Symposium %D 2014 %T Do dummies pay off? Limits of dummy traffic protection in anonymous communications %A Simon Oya %A Carmela Troncoso %A Fernando Pérez-González %K anonymous communications %K compass %K disclosure attacks %K dummies %B Privacy Enhancing Technologies Symposium %G eng %0 Conference Paper %B ICASSP2014 - Signal Processing for Communications and Networking (ICASSP2014 - SPCOM) %D 2014 %T FER prediction with variable codeword length %A Alberto Rico-Alvariño %A Robert W. Heath Jr. %A Carlos Mosquera %K adaptive signal processing %K compass %K dynacs %K Effective SNR %K FER prediction %K PHY abstraction %XFrame error rate (FER) prediction in wireless communication systems is an important tool with applications to system level simulations and link adaptation, among others. Although in realistic communication scenarios it is expected to have codewords of different lengths, previous work on FER prediction marginally treated the dependency of the FER on the codeword length. In this paper, we present a method to estimate the FER using codewords of different length. We derive a low complexity FER estimator for frames of different length transmitted over a binary symmetric channel of unknown error probability. We extend this technique to coded systems by the use of effective SNR FER predictors. The proposed estimation scheme is shown to outperform other simpler estimation methods.

%B ICASSP2014 - Signal Processing for Communications and Networking (ICASSP2014 - SPCOM) %C Florence, Italy %G eng %R 10.1109/ICASSP.2014.6853935 %0 Conference Paper %B IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP) %D 2014 %T Flat Fading Channel Estimation Based on Dirty Paper Coding %A Gabriel Domínguez-Conde %A Pedro Comesaña %A Fernando Pérez-González %K channel estimation %K dirty paper coding %K dynacs %K superimposed pilots %XA novel complex flat fading channel estimation scheme is proposed. Contrarily to previous schemes in the literature, this new approach is not based on introducing pilot sequences, but on reducing the interference caused by the information-bearing signal on the estimation-aiding signal by using Dirty Paper Coding. We show through simulations that our method outperforms the Partially-Data Dependent scheme, which is a state-of-the-art technique based on superimposed pilots.

%B IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP) %C Florence, Italy %G eng %R 10.1109/ICASSP.2014.6854852 %0 Conference Paper %B IEEE Sensor Array and Multichannel Signal Processing Workshop (SAM) %D 2014 %T How to Implement Doubly-Stochastic Matrices for Consensus-Based Distributed Algorithms %A S. Valcárcel-Macua %A C. Moreno-León %A J. S. Romero %A Silvana Silva Pereira %A Javier Zazo %A Alba Pagès-Zamora %A R. López-Valcarce %A S. Zazo %K compass %K dynacs %K wsn %XDoubly-stochastic matrices are usually required by

consensus-based distributed algorithms. We propose a simple

and efficient protocol and present some guidelines for implementing

doubly-stochastic combination matrices even in noisy,

asynchronous and changing topology scenarios. The proposed

ideas are validated with the deployment of a wireless sensor

network, in which nodes run a distributed algorithm for robust

estimation in the presence of nodes with faulty sensors.

%B IEEE Sensor Array and Multichannel Signal Processing Workshop (SAM)
%C A Coruña, Spain
%G eng
%R 10.1109/SAM.2014.6882409
%0 Journal Article
%J IEEE Transactions on Wireless Communications
%D 2014
%T Learning-Based Adaptive Transmission for Limited Feedback Multiuser MIMO-OFDM
%A Alberto Rico-Alvariño
%A Robert W. Heath Jr.
%K adaptive signal processing
%K dynacs
%B IEEE Transactions on Wireless Communications
%G eng
%R 10.1109/TWC.2014.2314104
%0 Journal Article
%J IEEE Transactions on Information Forensics and Security
%D 2014
%T A Least Squares Approach to the Static Traffic Analysis of High-Latency Anonymous Communication Systems
%A Fernando Pérez-González
%A Carmela Troncoso
%A Simon Oya
%B IEEE Transactions on Information Forensics and Security
%G eng
%R 10.1109/TIFS.2014.2330696
%0 Conference Paper
%B European Signal Processing Conference (EUSIPCO)
%D 2014
%T Low-Power Active Interference Cancellation for OFDM Spectrum Sculpting
%A Schmidt, J.F.
%A Daniel Romero
%A R. López-Valcarce
%X We present a low-power design for Active Interference

Cancellation (AIC) sculpting of the OFDM spectrum, based

on sparse design concepts. Optimal AIC designs compute

cancellation weights based on contributions from all data subcarriers.

Thus, as the number of subcarriers grows, power

consumption becomes a concern, and suboptimal solutions

that avoid involving all subcarriers are of interest. In this context,

we present novel sparse AIC designs based on a zeronorm

minimization of the matrix defining the cancellation

weights. These designs drastically reduce the number of operations

per symbol, and thus the power consumption, while allowing

to tune the loss with respect the optimal design. They

can be efficiently obtained and significantly outperform usual

thresholding or sparsity-inducing l_1-norm minimization approaches.

%B European Signal Processing Conference (EUSIPCO)
%8 09/2014
%G eng
%U http://www.eurasip.org/Proceedings/Eusipco/Eusipco2014/HTML/papers/1569912103.pdf
%0 Journal Article
%J IEEE Communications Magazine
%D 2014
%T MIMO precoding and combining solutions for millimeter wave systems
%A Ahmed Alkhateeb
%A Jianhua Mo
%A Nuria González-Prelcic
%A Robert W. Heath Jr.
%K adaptive signal processing
%K compass
%K mmWave
%X Millimeter-wave communication is one way to alleviate the spectrum gridlock at lower frequencies while simultaneously providing high-bandwidth communication channels. MmWave makes use of MIMO through large antenna arrays at both the base station and the mobile station to provide sufficient received signal power. This article explains how beamforming and precoding are different in MIMO mmWave systems than in their lower-frequency counterparts, due to different hardware constraints and channel characteristics. Two potential architectures are reviewed: hybrid analog/digital precoding/combining and combining with low-resolution analog- to-digital converters. The potential gains and design challenges for these strategies are discussed, and future research directions are highlighted.

%B IEEE Communications Magazine %V 52 %P 122-131 %8 12/2014 %G eng %N 12 %R 10.1109/MCOM.2014.6979963 %0 Conference Paper %B IEEE International Workshop on Information Forensics and Security (WIFS) %D 2014 %T Multiple JPEG compression detection by means of Benford-Fourier coefficients %A Cecilia Pasquini %A Giulia Boato %A Fernando Pérez-González %B IEEE International Workshop on Information Forensics and Security (WIFS) %C Atlanta, GA %8 12/2014 %G eng %0 Conference Paper %B IEEE Int. Workshop on Signal Processing Advances in Wireless Communications (SPAWC) %D 2014 %T Nearly-Optimal Compression Matrices for Signal Power Estimation %A Daniel Romero %A R. López-Valcarce %K cognitive radio %K dynacs %B IEEE Int. Workshop on Signal Processing Advances in Wireless Communications (SPAWC) %C Toronto, Canada %G eng %R 10.1109/SPAWC.2014.6941849 %0 Conference Paper %B IEEE International Conference on Image Processing (ICIP) %D 2014 %T A New Look At ML Step-Size Estimation for Scalar Costa Scheme Data Hiding %A Gabriel Domínguez-Conde %A Pedro Comesaña %A Fernando Pérez-González %B IEEE International Conference on Image Processing (ICIP) %C Paris, France %G eng %0 Thesis %D 2014 %T Neyman-Pearson Decision in Traffic Analysis %A Juan A. Elices %I University of New Mexico %C Albquerque, NM, USA %G eng %9 PhD Thesis %0 Conference Paper %B IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP) %D 2014 %T OFDM spectrum sculpting with active interference cancellation: Keeping spectral spurs at bay %A Schmidt, J.F. %A R. López-Valcarce %K cognitive radio %K dynacs %K spectrum shaping %B IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP) %I IEEE %C Florence, Italy %P 1-5 %8 05/2014 %G eng %R 10.1109/ICASSP.2014.6855169 %0 Thesis %D 2014 %T On-Ground Processing for Spectral Efficiency Improvement in Next Generation Satellite Communications %A Arnau, Jesus %K satcom %XThe eternal demand of improved spectrum exploitation for next generation satellite communications requires the study of techniques that are potentially able of a breakthrough. In this thesis we focus on two of the main issues hindering the performance of satellite communications.

In the first part of the thesis, we study the use of multi-user detection techniques in the return link of multibeam satellite systems operated with an aggressive frequency reuse strategy. We start by comparing their performance with respect to a traditional scenario, and study the possibility of splitting the processing between the gateway and the satellite to cope with practical constraints. We then study the fundamental performance limits of such a system when spatially correlated rain attenuation affects the users; analytical expressions are obtained for the high and low SNR regimes. Finally, we consider non perfect channel state information and obtain, through random matrix theory, an approximation of the residual error as a function of the system's parameters.

In the second part, we focus on link adaptation for mobile satellite communications. For the return link, we investigate the potential of open-loop channel state information, which is timely but scarcely accurate; the finding that this information is better than the traditional closed-loop one depending on the channel conditions motivated the study of an adaptive algorithm to dynamically balance both. Finally, in the forward link we considered the case where retransmissions are available, and designed the optimum modulation and coding scheme sequence for the different retransmissions of a packet in terms of throughput.

%I Universidade de Vigo
%C Vigo, Spain
%G eng
%9 PhD thesis
%0 Conference Paper
%B IEEE International Workshop on Information Forensics and Security (WIFS)
%D 2014
%T The optimal attack to histogram-based forensic detectors is simple(x)
%A Pedro Comesaña
%A Fernando Pérez-González
%K compass
%K Multimedia security
%B IEEE International Workshop on Information Forensics and Security (WIFS)
%C Atlanta, GA
%P 137-142
%8 12/2014
%G eng
%1 IEEE WIFS 2015 Best Paper Award

%0 Journal Article %J IEEE Transactions on Wireless Communications %D 2014 %T Performance of the Multibeam Satellite Return Link with Correlated Rain Attenuation %A Arnau, Jesus %A Christopoulos, D. %A Chatzinotas, S. %A C. Mosquera %A Ottersten, B. %K Antennas %K Approximation methods %K Attenuation %K Correlation %K dynacs %K Rain %K satcom %K Satellites %K Signal to noise ratio %XRain attenuation is among the major impairments for satellite systems operating in the K band and above. In this paper, we investigate the impact of spatially correlated rain attenuation on the performance of a multibeam satellite return link. For a comprehensive assessment, an analytical model for the antenna pattern that generates the beams is also proposed. We focus on the outage capacity of the link, and obtain analytical approximations at high and low SNR. The derived approximations provide insights on the effect of key system parameters – like the inter-user distance, the satellite beam radius, or the rain intensity– and simulation results show that it fits tightly to the Monte Carlo results. Additionally, the derived expressions can be easily particularized for the single-user case, providing some novel insights.

%B IEEE Transactions on Wireless Communications %P 1-1 %G eng %R 10.1109/TWC.2014.2329682 %0 Conference Paper %B IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) %D 2014 %T Power spectrum blind sampling using optimal multicoset sampling patterns in the MSE sense %A Bamrung TauSiesakul %A Nuria González-Prelcic %K cognitive radio %K dynacs %B IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) %G eng %R 10.1109/ICASSP.2014.6853758 %0 Conference Paper %B IEEE International New Circuits and Systems Conference (NEWCAS) %D 2014 %T Sensitivity of compressive sensing architectures based on time interleaved analog-to-digital converters to channel mismatches %A Roi Méndez-Rial %A J.M. Caurel-Carrera %A Nuria González-Prelcic %K dynacs %B IEEE International New Circuits and Systems Conference (NEWCAS) %G eng %R 10.1109/NEWCAS.2014.6933981 %0 Conference Paper %B IEEE Sensor Array and Multichannel Signal Processing Workshop (SAM) %D 2014 %T SINR Optimization in Wideband Full-Duplex MIMO Relays under Limited Dynamic Range %A Emilio Antonio-Rodríguez %A R. López-Valcarce %A Taneli Riihonen %A Stefan Werner %A Risto Wichman %K adaptive signal processing %K compass %K full duplex %B IEEE Sensor Array and Multichannel Signal Processing Workshop (SAM) %C A Coruña, Spain %G eng %R 10.1109/SAM.2014.6882369 %0 Journal Article %J IEEE Trans. on Vehicular Technology %D 2014 %T Spectrum Sensing for Wireless Microphone Signals using Multiple Antennas %A Daniel Romero %A R. López-Valcarce %K cognitive radio %K dynacs %X Spectrum sensors for cognitive radio are expected to deploy multiple antennas in order to overcome the noise uncertainty problem and minimize the effects of small-scale fading. Despite the requirement that these sensors must detect wireless microphone (WM) signals, works in the literature have focused either on general purpose multiantenna detectors, or single antenna WM detectors. We exploit the spatial structure and particular properties of WM waveforms to derive four multiantenna detectors for WM signals with different performance/ complexity tradeoffs. These detectors are based on the generalized likelihood ratio test, which is derived under several signal models exploiting either the fact that the bandwidth of a WM signal never exceeds 200 kHz, the property that these signals have a constant magnitude, or both. The proposed detectors do not require synchronization with the WM signal and are robust to the noise uncertainty problem as well as to small-scale fading. Using the simulation guidelines from the IEEE 802.22 standard, the novel multiantenna WM detectors are shown to outperform previous schemes, thus demonstrating the advantages of exploiting spatial correlation along with WM signal structure. %B IEEE Trans. on Vehicular Technology %V 63 %P 4395-4407 %8 11/2014 %G eng %N 9 %& 4395 %R 10.1109/TVT.2014.2316513 %0 Report %D 2014 %T Technical Report TSC/FPG/20032014: Performance Analysis of the Least Squares Disclosure Attack with Time-Varying User Behavior %A Fernando Pérez-González %A Carmela Troncoso %A Simon Oya %G eng %0 Report %D 2014 %T Technical Report TSC/SO/02052014: Derivation of the Mean Squared Error of the Least Squares Estimator in a Timed Pool Mix with Dummy Traffic %A Simon Oya %A Carmela Troncoso %A Fernando Pérez-González %G eng %0 Report %D 2014 %T Technical Report UV/TSC/APU/02102014: Multivariate Ring Learning with Errors %A Alberto Pedrouzo-Ulloa %A Juan Ramón Troncoso-Pastoriza %A Fernando Pérez-González %I University of Vigo %G eng %0 Conference Paper %B IEEE International Conference on Audio, Speech, and Signal Processing (ICASSP) %D 2014 %T Transportation-theoretic image counterforensics to first significant digit histogram forensics %A Cecilia Pasquini %A Pedro Comesaña %A Fernando Pérez-González %B IEEE International Conference on Audio, Speech, and Signal Processing (ICASSP) %I IEEE %C Florence, Italy %8 05/2014 %G eng %0 Conference Paper %B IEEE Workshop on Information Forensics and Security %D 2014 %T Understanding the Effects of Real-World Behavior in Statistical Disclosure Attacks %A Simon Oya %A Carmela Troncoso %A Fernando Pérez-González %B IEEE Workshop on Information Forensics and Security %G eng %0 Conference Paper %B IEEE 14th Int. Workshop on Signal Processing Advances in Wireless Communications (SPAWC) %D 2013 %T Adaptive Self-interference Cancellation in Wideband Full-Duplex Decode-and-Forward MIMO Relays %A Emilio Antonio-Rodríguez %A R. López-Valcarce %A Taneli Riihonen %A Stefan Werner %A Risto Wichman %K adaptive signal processing %K dynacs %K full duplex %B IEEE 14th Int. Workshop on Signal Processing Advances in Wireless Communications (SPAWC) %C Darmstadt, Germany %8 06/2013 %G eng %R 10.1109/SPAWC.2013.6612074 %0 Conference Paper %B The Tenth International Symposium on Wireless Communication Systems 2013 (ISWCS 2013) %D 2013 %T Analytical Characterization of the Single Frequency Network Gain Using Effective SNR Metrics %A Alberto Rico-Alvariño %A C. Mosquera %K broadcasting %K dynacs %K Effective SNR metrics %K Single Frequency Network %XThe design of broadcasting networks operating in a single frequency way is challenging due to the difficulty of predicting the performance in a frequency selective channel, caused by natural multipath and echoes coming from different transmitters. In this paper we resort to the use of frame error rate prediction metrics (also known as effective SNR metrics) to characterize the performance gain (or loss) under different multipath and SNR regimes in a simplified scenario with two transmitters. The analysis shows clearly that receivers with a dominant line of sight reception and high SNR are more sensitive to the presence of echoes, while those users in low SNR or strong multipath conditions are easily enforced by the insertion of a second transmitter.

%B The Tenth International Symposium on Wireless Communication Systems 2013 (ISWCS 2013) %C Ilmenau, Germany %G eng %0 Conference Paper %B Int. Conf. Acoust., Speech, Signal Process. (ICASSP) %D 2013 %T Autocorrelation-based adaptation rule for feedback equalization in Wideband Full-Duplex Amplify-and-Forward MIMO relays %A Emilio Antonio-Rodríguez %A R. López-Valcarce %A Taneli Riihonen %A Stefan Werner %A Risto Wichman %K adaptive signal processing %K dynacs %K full duplex %XSimultaneous reception and transmission in the same frequency, so-called full-duplex operation, causes an infinite feedback loop in an amplify-and-forward relay. The unwanted echoes may result in oscillation at the relay, making it unstable, and distorting the spectrum. This paper presents an adaptive MIMO filtering method for full-duplex amplify-and-forward relays that aims at solving the joint problem of self-interference mitigation and equalization of the source-relay channel. The scheme exploits knowledge of the autocorrelation of the transmitted signal as the only side information while allowing the relay, in the best case, to implement precoding as if there was not any self-interference or frequency selectivity in the source-relay channel. Finally, the proposed adaptation algorithm is investigated by determining its stationary points and by performing simulations in a MIMO-OFDM framework.

%B Int. Conf. Acoust., Speech, Signal Process. (ICASSP)
%G eng
%R 10.1109/ICASSP.2013.6638606
%0 Conference Paper
%B Int. Conf. Acoust., Speech, Signal Process. (ICASSP)
%D 2013
%T Cancelling self-interference in full-duplex relays without Angle-of-Arrival information
%A Emilio Antonio-Rodríguez
%A R. López-Valcarce
%K adaptive signal processing
%K dynacs
%K full duplex
%X With full-duplex relays, simultaneous reception and transmission in

the same frequency produce self-interference distortion and relay oscillation,

hampering reception at the receiver end unless properly

mitigated. Previous adaptive methods for self-interference cancellation

using multiple receive antennas require knowledge of the direction

of arrival of the source signal. We present a novel architecture

and adaptive scheme for Amplify-and-Forward relays allowing cancellation

without such knowledge. The temporal filter is updated

under the property restoral paradigm in order to match the power

spectrum of the retransmitted signal to that of the source signal.

%B Int. Conf. Acoust., Speech, Signal Process. (ICASSP)
%G eng
%R 10.1109/ICASSP.2013.6638558
%0 Journal Article
%J IEEE Journal on Emerging and Selected Topics in Circuits and Systems
%D 2013
%T Choose Your Subcarriers Wisely: Active Interference Cancellation for Cognitive OFDM
%A Schmidt, J.F.
%A Costas-Sanz, S.
%A R. López-Valcarce
%K cognitive radio
%K dynacs
%K spectrum shaping
%B IEEE Journal on Emerging and Selected Topics in Circuits and Systems
%V 3
%P 615-625
%8 12/2013
%G eng
%N 4
%& 615
%R 10.1109/JETCAS.2013.2280808
%0 Conference Paper
%B European Signal Processing Conf. (EUSIPCO), Marrakech (Morocco)
%D 2013
%T A Class of Circular Sparse Rulers for Compressive Power Spectrum Estimation
%A M. Elena Domínguez-Jiménez
%A Nuria González-Prelcic
%K cognitive radio
%K dynacs
%B European Signal Processing Conf. (EUSIPCO), Marrakech (Morocco)
%8 09/2013
%G eng
%0 Journal Article
%J Sensors
%D 2013
%T A Cognitive Mobile BTS Solution with Software-Defined Radioelectric Sensing
%A J. Muñoz
%A J. Vales-Alonso
%A F. Quiñoy-García
%A Costas-Sanz, S.
%A M. Pillado
%A F.J. González-Castaño
%A M. García-Sanchez
%A R. López-Valcarce
%A C. López-Bravo
%K cognitive radio
%K dynacs
%K mobile communications
%K SDR
%K vehicular communications
%X Private communications inside large vehicles such as ships may be effectively provided using standard cellular systems. In this paper we propose a new solution based on software-defined radio with electromagnetic sensing support. Software-defined radio allows low-cost developments and, potentially, added-value services not available in commercial cellular networks. The platform of reference, OpenBTS, only supports single-channel cells. Our proposal, however, has the ability of changing BTS channel frequency without disrupting ongoing communications. This ability should be mandatory in vehicular environments, where neighbouring cell configurations may change rapidly, so a moving cell must be reconfigured in real-time to avoid interferences. Full details about frequency occupancy sensing and the channel reselection procedure are provided in this paper. Moreover, a procedure for fast terminal detection is proposed. This may be decisive in emergency situations, e.g., if someone falls overboard. Different tests confirm the feasibility of our proposal and its compatibility with commercial GSM terminals.

%B Sensors %V 13 %P 2051-2075 %8 02/2013 %G eng %N 2 %& 2051 %R 10.3390/s130202051 %0 Conference Paper %B IEEE Int. Workshop Comput. Advances Multi-Sensor Adaptive Process (CAMSAP) %D 2013 %T Compressive Angular and Frequency Periodogram Reconstruction for Multiband Signals %A Ariananda, D. D. %A Daniel Romero %A Geert Leus %K cognitive radio %K dynacs %B IEEE Int. Workshop Comput. Advances Multi-Sensor Adaptive Process (CAMSAP) %C San Martin %G eng %R 10.1109/CAMSAP.2013.6714102 %0 Conference Paper %B Inform. Theory Appl. Workshop %D 2013 %T Compressive Covariance Sampling %A Daniel Romero %A Geert Leus %K cognitive radio %K dynacs %B Inform. Theory Appl. Workshop %P 1-8 %8 Feb. %G eng %R 10.1109/ITA.2013.6502949 %0 Conference Paper %B Int. Conf. Acoust., Speech, Signal Process. (ICASSP) %D 2013 %T Compressive wideband spectrum sensing with spectral prior information %A Daniel Romero %A R. López-Valcarce %A Geert Leus %K cognitive radio %K dynacs %K spectrum sensing %XWideband spectrum sensing provides a means to determine

the occupancy of channels spanning a broad range of frequencies.

Practical limitations impose that the acquisition should

be accomplished at a low rate, much below the Nyquist lower

bound. Dramatic rate reductions can be obtained by the observation

that only a few parameters need to be estimated in

typical spectrum sensing applications. This paper discusses

the joint estimation of the power of a number of channels,

whose power spectral density (PSD) is known up to a scale

factor, using compressive measurements. First, relying on

a Gaussian assumption, an efficient approximate maximum

likelihood (ML) technique is presented. Next, a least-squares

estimator is applied for the general non-Gaussian case.

%B Int. Conf. Acoust., Speech, Signal Process. (ICASSP)
%G eng
%R 10.1109/ICASSP.2013.6638505
%0 Conference Paper
%B IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)
%D 2013
%T Coping with the enemy: Advances in adversary-aware signal processing
%A Mauro Barni
%A Fernando Pérez-González
%B IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)
%C Vancouver, Canada
%P 8682–8686
%8 05/2013
%G eng
%U http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6639361
%0 Conference Proceedings
%B Asilomar Conference on Signals Systems and Computers
%D 2013
%T Cross Layer Link Adaptation in Time Varying Mobile Satellite Channels with Statistical and Outdated CSIT
%A Alberto Rico-Alvariño
%A J. Arnau
%A Carlos Mosquera
%K dynacs
%K satcom
%B Asilomar Conference on Signals Systems and Computers
%G eng
%R 10.1109/ACSSC.2013.6810481
%0 Journal Article
%J Engineering Applications of Artificial Intelligence
%D 2013
%T On the design of a novel two-objective harmony search approach for distance- and connectivity-based localization in wireless sensor networks
%A Diana Manjarres
%A Javier Del Ser
%A Sergio Gil-Lopez
%A Massimo Vecchio
%A Itziar Landa-Torres
%A Sancho Salcedo-Sanz
%A R. López-Valcarce
%K dynacs
%K wsn
%B Engineering Applications of Artificial Intelligence
%V 26
%P 669-676
%8 02/2013
%G eng
%N 2
%& 669
%R 10.1016/j.engappai.2012.06.002
%0 Conference Paper
%B Int. Conf. Acoust., Speech, Signal Process. (ICASSP)
%D 2013
%T A Diffusion-based distributed EM algorithm for density estimation in wireless sensor networks
%A Silvana Silva Pereira
%A Alba Pagès-Zamora
%A R. López-Valcarce
%K dynacs
%K wsn
%X Distributed implementations of the Expectation-Maximization

(EM) algorithm reported in the literature have been proposed for

applications to solve specific problems. In general, a primary

requirement to derive a distributed solution is that the

structure of the centralized version enables the computation

involving global information in a distributed fashion. This

paper treats the problem of distributed estimation of Gaussian

densities by means of the EM algorithm in wireless sensor

networks using diffusion strategies, where the information

is gradually diffused across the network for the computation

of the global functions. The low-complexity implementation

presented here is based on a two time scale operation

for information averaging and diffusion. The convergence to

a fixed point of the centralized solution has been studied and

the appealing results motivates our choice for this model. Numerical

examples provided show that the performance of the

distributed EM is, in practice, equal to that of the centralized

scheme.

%B Int. Conf. Acoust., Speech, Signal Process. (ICASSP)
%G eng
%R 10.1109/ICASSP.2013.6638501
%0 Journal Article
%J IEEE Signal Processing Letters
%D 2013
%T A Diffusion-Based EM Algorithm for Distributed Estimation in Unreliable Sensor Networks
%A Silvana Silva Pereira
%A R. López-Valcarce
%A Alba Pagès-Zamora
%K dynacs
%K wsn
%X We address the problem of distributed estimation of a parameter from a set of noisy observations collected by a sensor network, assuming that some sensors may be subject to data failures and report only noise. In such scenario, simple schemes such as the Best Linear Unbiased Estimator result in an error floor in moderate and high signal-to-noise ratio (SNR), whereas previously proposed methods based on hard decisions on data failure events degrade as the SNR decreases. Aiming at optimal performance within the whole range of SNRs, we adopt a Maximum Likelihood framework based on the Expectation-Maximization (EM) algorithm. The statistical model and the iterative nature of the EM method allow for a diffusion-based distributed implementation, whereby the information propagation is embedded in the iterative update of the parameters. Numerical examples show that the proposed algorithm practically attains the Cramer–Rao Lower Bound at all SNR values and compares favorably with other approaches.

%B IEEE Signal Processing Letters %V 20 %P 595-598 %8 06/2013 %G eng %N 6 %& 595 %R 10.1109/LSP.2013.2260329 %0 Conference Paper %B IEEE International Workshop on Information Forensics and Security (WIFS) %D 2013 %T The flow fingerprinting game %A Juan A. Elices %A Fernando Pérez-González %B IEEE International Workshop on Information Forensics and Security (WIFS) %C Guangzhou, China %P 97–102 %8 11/2013 %G eng %0 Conference Paper %B IEEE International Conference on Image Processing %D 2013 %T Forensic analysis of full-frame linearly filtered JPEG images %A Valentina Conotter %A Pedro Comesaña %A Fernando Pérez-González %K JPEG compression %K linear filtering %B IEEE International Conference on Image Processing %C Melbourne, Australia %P 4517-4521 %8 JPEG compression %G eng %0 Journal Article %J IEEE Transactions on Information Forensics and Security %D 2013 %T Fully Private Noninteractive Face Verification %A Juan Ramón Troncoso-Pastoriza %A Daniel González-Jiménez %A Fernando Pérez-González %K SPED %B IEEE Transactions on Information Forensics and Security %V 8 %P 1101-1114 %8 07/2013 %G eng %N 7 %1To appear

%0 Conference Paper %B IEEE International Workshop on Information Forensics and Security %D 2013 %T Joint detection of full-frame linear filtering and JPEG compression in digital images %A Valentina Conotter %A Pedro Comesaña %A Fernando Pérez-González %B IEEE International Workshop on Information Forensics and Security %I IEEE %C Guangzhou, China %8 11/2013 %G eng %0 Journal Article %J EURASIP Journal on Advances in Signal Processing %D 2013 %T Lattice implementation of adaptive channel shortening in multicarrier transmission over IIR channels %A E. Ben Salem %A S. Cherif %A H. Besbes %A R. López-Valcarce %B EURASIP Journal on Advances in Signal Processing %V 2013:174 %8 11/2013 %G eng %U http://asp.eurasipjournals.com/content/2013/1/174 %R 10.1186/1687-6180-2013-174 %0 Conference Paper %B 21st European Signal Processing Conference 2013 (EUSIPCO 2013) %D 2013 %T Learning Based Link Adaptation in Multiuser MIMO-OFDM %A Alberto Rico-Alvariño %A Robert W. Heath Jr. %K dynacs %K link adaptation %K Machine Learning %K Multiuser MIMO-OFDM %XLink adaptation in multiple user multiple-input multiple-output orthogonal frequency division multiplexing communication systems is challenging because of the coupling between user selection, mode selection, precoding, and equalization. In this paper, we present a methodology to perform link adaptation under this multiuser setting, focusing on the capabilities of IEEE 802.11ac. We propose to use a machine learning classifier to solve the problem of selecting a proper modulation and coding scheme, combined with a greedy algorithm that performs user and spatial mode selection. We observe that our solution offers good performance in the case of perfect channel state information or high feedback rate, while those scenarios with less feedback suffer some degradation due to inter-user interference.

%B 21st European Signal Processing Conference 2013 (EUSIPCO 2013) %C Marrakech, Morocco %G eng %0 Report %D 2013 %T Least Squares Disclosure Attacks: User Profiling for Mix-based Anonymous Communication Systems %A Fernando Pérez-González %A Carmela Troncoso %I University of Vigo %C Vigo %8 01/2013 %G eng %0 Conference Paper %B Asilomar Conference on Signals Systems and Computers %D 2013 %T Link Adaptation in MIMO-OFDM with Practical Impairments %A Alberto Rico-Alvariño %A Robert W. Heath Jr. %K dynacs %K link adaptation %K MIMO-OFDM %B Asilomar Conference on Signals Systems and Computers %G eng %R 10.1109/ACSSC.2013.6810579 %0 Conference Paper %B IEEE International Workshop on Multimedia Signal Processing (MMSP) %D 2013 %T Localization of Forgeries in MPEG-2 Video through GOP Size and DQ analysis %A Daniele Labartino %A Tiziano Bianchi %A Alessia De Rosa %A Marco Fontani %A David Vázquez-Padín %A Alessandro Piva %A Mauro Barni %XThis work addresses forgery localization in MPEG-2 compressed videos. The proposed method is based on the analysis of Double Quantization (DQ) traces in frames that were encoded twice as intra (i.e., I-frames). Employing a state-of-the-art method, such frames are located in the video under analysis by estimating the size of the Group Of Pictures (GOP) that was used in the first compression; then, the DQ analysis is devised for the MPEG-2 encoding scheme and applied to frames that were intra-coded in both the first and second compression. In such a way, regions that were manipulated between the two encodings are detected. Compared to existing methods based on double quantization analysis, the proposed scheme makes forgery localization possible on a wider range of settings.

**Top 10% Award**

Submitted

%0 Journal Article %J Communications Letters, IEEE %D 2013 %T MMSE Performance Analysis of Generalized Multibeam Satellite Channels %A Christopoulos, D. %A J. Arnau %A Chatzinotas, S. %A C. Mosquera %A Ottersten, B. %K dynacs %K linear minimum mean square error receivers %K multibeam satellites %K Multiuser detection %K return link %K satcom %B Communications Letters, IEEE %P 1-4 %G eng %R 10.1109/LCOMM.2013.052013.122658 %0 Conference Proceedings %B 2013 IEEE International Workshop on Information Forensics and Security (WIFS) %D 2013 %T Near optimal detection of quantized signals and application to JPEG forensics %A Tiziano Bianchi %A Alessandro Piva %A Fernando Pérez-González %B 2013 IEEE International Workshop on Information Forensics and Security (WIFS) %C Guangzhou, China %P 168-173 %8 11/2013 %G eng %U http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6707813 %0 Journal Article %J Soft Computing %D 2013 %T A novel heuristic approach for distance- and connectivity-based multihop node localization in wireless sensor networks %A Diana Manjarres %A Javier Del Ser %A Sergio Gil-Lopez %A Massimo Vecchio %A Itziar Landa-Torres %A R. López-Valcarce %K dynacs %K wsn %B Soft Computing %V 17 %P 17-28 %8 01/2013 %G eng %N 1 %& 17 %R 10.1007/s00500-012-0897-2 %0 Conference Paper %B 31st AIAA International Communications Satellite Systems Conference %D 2013 %T Open Loop Adaptive Coding and Modulation for Mobile Satellite Return Links %A Arnau, Jesus %A Carlos Mosquera %K dynacs %K link adaptation %K satcom %B 31st AIAA International Communications Satellite Systems Conference %I American Institute of Aeronautics and Astronautics %C Florence, Italy %G eng %1http://dx.doi.org/10.2514/6.2013-5704

%R doi:10.2514/6.2013-5704 %0 Conference Paper %B IEEE International Conference on Audio, Speech and Signal Processing %D 2013 %T Optimal counterforensics for histogram-based forensics %A Pedro Comesaña %A Fernando Pérez-González %B IEEE International Conference on Audio, Speech and Signal Processing %I IEEE %C Vancouver, Canada %P 3048-3052 %G eng %0 Conference Paper %B Asilomar Conference on Signals, Systems and Computers %D 2013 %T Power Spectrum Blind Sampling Using Minimum Mean Square Error and Weighted Least Squares %A Bamrung TauSiesakul %A Nuria González-Prelcic %K cognitive radio %K dynacs %B Asilomar Conference on Signals, Systems and Computers %8 11/2013 %G eng %R 10.1109/ACSSC.2013.6810249 %0 Journal Article %J IEEE Signal Processing Magazine %D 2013 %T Privacy-Preserving Data Aggregation in Smart Metering Systems: An Overview %A Zekeriya Erkin %A Juan Ramón Troncoso-Pastoriza %A Reginald Lagendijk %A Fernando Pérez-González %K SPED %B IEEE Signal Processing Magazine %V 30 %P 75-86 %8 03/2013 %G eng %N 2 %0 Conference Paper %B IEEE International Conference on Image Processing %D 2013 %T Quantization lattice estimation for multimedia forensics %A Pedro Comesaña %A Fernando Pérez-González %A Noelia Liste %K Dual lattice %K lattice estimation %K multimedia forensics %K noisy estimation %B IEEE International Conference on Image Processing %C Melbourne, Australia %P 4452-4456 %G eng %0 Journal Article %J IEEE Signal Processing Magazine %D 2013 %T Secure Signal Processing in the Cloud: enabling technologies for privacy-preserving multimedia cloud processing %A Juan Ramón Troncoso-Pastoriza %A Fernando Pérez-González %K SPED %B IEEE Signal Processing Magazine %V 30 %P 29-41 %8 03/2013 %G eng %N 2 %0 Conference Paper %B IEEE International Workshop on Information Forensics and Security (WIFS) %D 2013 %T Set-Membership Identification of Resampled Signals %A David Vázquez-Padín %A Pedro Comesaña %A Fernando Pérez-González %XThe problem of resampling factor estimation as a means for tampering detection has been largely investigated. Most of the existing techniques rely on the analysis of cyclic correlations induced in the resampled signal. However, in this paper, a new direction is explored by addressing the same problem in terms of the set-membership estimation theory. The proposed technique constructs a model of the problem using available a priori knowledge and in consonance with a finite number of observations that comes from the resampled signal under study. With this information, the proposed technique is able to provide an estimate of the resampling factor applied to the original signal and, if required, an estimate of such signal and an estimate of the interpolation filter. The performance in terms of accuracy and MSE of the proposed approach is evaluated and comparative results with state-of-the-art methods are reported.

Link adaptation in mobile satellite channels is difficult because of the large propagation delays, the frequent signal blockage and the variation of the channel statistics. In this paper, we propose a cross-layer link adaptation strategy that exploits statistical, long-term CSI to increase the throughput when some retransmissions are available; this increase is obtained while meeting a target outage probability constraint. Our strategy takes as inputs the estimated packet error rates of the available modulation and coding schemes (MCS) and their rates; as an output, it returns the optimum sequence of MCS to be used. Results will also show that simple information acquisition strategies can still provide very good results.

%B Globecom 2013 - Symposium on Selected Areas in Communications (GC13 SAC) %C Atlanta, USA %G eng %R 10.1109/GLOCOM.2013.6831502 %0 Conference Paper %B IEEE International Workshop on Multimedia Signal Processing %D 2013 %T Taking advantage of source correlation in forensic analysis %A Pedro Comesaña %A Fernando Pérez-González %B IEEE International Workshop on Multimedia Signal Processing %C Pula (Sardinia), Italy %P 159-164 %G eng %0 Journal Article %J IEEE Trans. Signal Process. %D 2013 %T Wideband Spectrum Sensing From Compressed Measurements Using Spectral Prior Information %A Daniel Romero %A Geert Leus %K cognitive radio %K compressed sensing %K dynacs %K spectrum sensing %B IEEE Trans. Signal Process. %V 61 %P 6232-6246 %G eng %R 10.1109/TSP.2013.2283473 %0 Journal Article %J IEEE J. Selected Areas in Communications %D 2012 %T An Adaptive Feedback Canceller for Full-Duplex Relays Based on Spectrum Shaping %A R. López-Valcarce %A Emilio Antonio-Rodríguez %A C. Mosquera %A Fernando Pérez-González %K adaptive signal processing %K dynacs %K full duplex %XAlthough full-duplex relaying schemes are appealing in order to improve spectral efficiency, simultaneous reception and transmission in the same frequency results in selfinterference,

distorting the retransmitted signal and making the relay prone to oscillation. Current feedback cancellation techniques by means of adaptive filters are hampered by the fact that the useful and interference signals are highly correlated. We present a new adaptive algorithm which effectively and blindly

restores the spectral shape of the desired signal. In contrast

with previous schemes, the novel adaptive feedback canceller has low complexity, does not introduce additional delay in the relay station, and partly compensates for multipath propagation.

%B IEEE J. Selected Areas in Communications
%V 30
%P 1566 - 1577
%8 08/2012
%G eng
%N 8
%R 10.1109/JSAC.2012.120923
%0 Conference Paper
%B IEEE 13th Int. Workshop on Signal Processing Advances in Wireless Communications (SPAWC 2012)
%D 2012
%T Adaptive self-interference suppression for full-duplex relays with multiple receive antennas
%A Emilio Antonio-Rodríguez
%A R. López-Valcarce
%K adaptive signal processing
%K dynacs
%K full duplex
%X In full-duplex relays, simultaneous reception and transmission

in the same frequency results in self-interference which distorts the retransmitted signal and makes the relay prone to oscillation. We present an adaptive feedback canceller for multiple-input single-output (MISO) relays, efficiently combining spatial and temporal processing. The receive array is adaptively steered towards the minimum variance distortionless response (MVDR), whereas the temporal filter update is based on a novel low-complexity spectrum shaping scheme which avoids introducing additional delay in the relay station.

%B IEEE 13th Int. Workshop on Signal Processing Advances in Wireless Communications (SPAWC 2012)
%I IEEE
%C Çesme, Turkey
%8 07/2012
%G eng
%R 10.1109/SPAWC.2012.6292948
%0 Conference Paper
%B 30th AIAA International Communications Satellite Systems Conference (ICSSC)
%D 2012
%T Adaptive Transmission Techniques for Mobile Satellite Links
%A Arnau, Jesus
%A Alberto Rico-Alvariño
%A C. Mosquera
%K dynacs
%K satcom
%B 30th AIAA International Communications Satellite Systems Conference (ICSSC)
%C Ottawa, Canada
%G eng
%1

We consider the problem of developing efﬁcient sampling

schemes for multiband sparse signals. Previous results on

multicoset sampling implementations that lead to universal

sampling patterns (which guarantee perfect reconstruction),

are based on a set of appropriate interleaved analog to digital converters, all of them operating at the same sampling

frequency. In this paper we propose an alternative multirate

synchronous implementation of multicoset codes, that is, all

the analog to digital converters in the sampling scheme operate at different sampling frequencies, without need of introducing any delay. The interleaving is achieved through the

usage of different rates, whose sum is signiﬁcantly lower than

the Nyquist rate of the multiband signal. To obtain universal

patterns the sampling matrix is formulated and analyzed. Appropriate choices of the parameters, that is the block length

and the sampling rates, are also proposed

%B European Signal Processing Conference (EUSIPCO 2012)
%P 1184-1188
%8 08/2012
%G eng
%0 Conference Paper
%B IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)
%D 2012
%T Design of universal multicoset sampling patterns for compressed sensing of multiband sparse signals
%A M. Elena Domínguez-Jiménez
%A Nuria González-Prelcic
%A Gonzalo Vázquez-Vilar
%A R. López-Valcarce
%X Many problems in digital communications involve wideband radio signals. As the most recent example, the impressive advances in Cognitive Radio systems make even more necessary the development of sampling schemes for wideband radio signals with spectral holes. This is equivalent to considering a sparse multiband signal in the framework of Compressive Sampling theory. Starting from previous results on multicoset sampling and recent advances in compressive sampling, we analyze the matrix involved in the corresponding reconstruction equation and define a new method for the design of universal multicoset codes, that is, codes guaranteeing perfect reconstruction of the sparse multiband signal.

%B IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) %C Kyoto (Japan) %P 3337 - 3340 %8 03/2012 %@ 978-1-4673-0044-5 %G eng %R 10.1109/ICASSP.2012.6288630 %0 Conference Paper %B IEEE Workshop on Information Forensics and Security %D 2012 %T Detection and information theoretic measures for quantifying the distinguishability between multimedia operator chains %A Pedro Comesaña %B IEEE Workshop on Information Forensics and Security %I IEEE %C Tenerife, Spain %G eng %0 Conference Paper %B IEEE Statistical Signal Processing Workshop (SSP 2012) %D 2012 %T Detection of Gaussian signals in unknown time-varying channels %A Daniel Romero %A Javier Vía %A R. López-Valcarce %A Ignacio Santamaría %K cognitive radio %K dynacs %K spectrum sensing %XDetecting the presence of a white Gaussian signal distorted by a noisy time-varying channel is addressed by means of three different detectors. First, the generalized likelihood ratio test (GLRT) is found for the case where the channel has no temporal structure, resulting in the well-known Bartlett’s test. Then it is shown that, under the transformation group given by scaling factors, a locally most powerful invariant test (LMPIT) does not exist. Two alternative approaches are explored in the low signal-to-noise ratio (SNR) regime: the first assigns a prior probability density function (pdf) to the channel (hence modeled as random), whereas the second assumes an underlying basis expansion model (BEM) for the (now deterministic) channel and obtains the maximum likelihood (ML) estimates of the parameters relevant for the detection problem. The performance of these detectors is evaluated via Monte Carlo simulation.

%B IEEE Statistical Signal Processing Workshop (SSP 2012)
%I IEEE
%C Ann Arbor, MI
%8 08/2012
%G eng
%R 10.1109/SSP.2012.6319858
%0 Conference Paper
%B 3rd Int. Workshop on Cognitive Information Processing (CIP 2012)
%D 2012
%T Detection of unknown constant magnitude signals in time-varying channels
%A Daniel Romero
%A R. López-Valcarce
%K cognitive radio
%K dynacs
%K spectrum sensing
%X Spectrum sensing constitutes a key ingredient in many cognitive radio paradigms in order to detect and protect primary transmissions. Most sensing schemes in the literature assume a time-invariant channel. However, when operating in low Signal-to-Noise Ratio (SNR) conditions, observation times are necessarily long and may become larger than the coherence time of the channel. In this paper the problem of detecting an unknown constant-magnitude waveform in frequency-flat time-varying channels with noise background of unknown variance is considered. The channel is modeled using a basis expansion model (BEM) with random coefficients. Adopting a generalized likelihood ratio (GLR) approach in order to deal with nuisance parameters, a non-convex optimization problem results. We discuss different possibilities to circumvent this problem, including several low complexity approximations to the GLR test as well as an efficient fixed-point iterative method to obtain the true GLR statistic. The approximations exhibit a performance ceiling in terms of probability of detection as the SNR increases, whereas the true GLR test does not. Thus, the proposed fixed-point iteration constitutes the preferred choice in applications requiring a high probability of detection.

%B 3rd Int. Workshop on Cognitive Information Processing (CIP 2012) %C Baiona, Spain %8 05/2012 %G eng %R 10.1109/CIP.2012.6232933 %0 Conference Paper %B IEEE International Workshop on Information Forensics and Security (WIFS) %D 2012 %T Detection of video double encoding with GOP size estimation %A David Vázquez-Padín %A Marco Fontani %A Tiziano Bianchi %A Pedro Comesaña %A Alessandro Piva %A Mauro Barni %XVideo forensics is an emerging discipline, that aims at inferring information about the processing history undergone by a digital video in a blind fashion. In this work we introduce a new forensic footprint and, based on it, propose a method for detecting whether a video has been encoded twice; if this is the case, we also estimate the size of the Group Of Pictures (GOP) employed during the first encoding. As shown in the experiments, the footprint proves to be very robust even in realistic settings (i.e., when encoding is carried out using typical compression rates), that are rarely addressed by existing techniques.

%B IEEE International Workshop on Information Forensics and Security (WIFS) %I IEEE %C Tenerife, Spain %P 151-156 %8 12/2012 %G eng %0 Conference Paper %B 2012 6th Advanced Satellite Multimedia Systems Conference (ASMS) and 12th Signal Processing for Space Communications Workshop (SPSC) (ASMS/SPSC 2012) %D 2012 %T On the Effect of Echoes in Hybrid Terrestrial-Satellite Single Frequency Networks: Analysis and Countermeasures %A Alberto Rico-Alvariño %A C. Mosquera %K dynacs %K Effective SNR %K Hybrid Terrestrial- Satellite %K satcom %K Satellite OFDM %K Single Frequency Network %K Space-Time Coding %XHybrid Terrestrial Satellite Single Frequency Networks achieve large spectral efficiencies due to a higher frequency reuse, which is attained by transmitting the same waveform in the same frequency band from satellite and terrestrial transmitters. However, the presence of multiple transmitters propitiates the existence of the so-called SFN echoes, which can degrade the system performance even if they arrive within the OFDM guard interval. In this paper we characterize this effect by resorting to PER prediction metrics (or effective SNR metrics), and analyze two simple preprocessing schemes that mitigate this degradation: the use of Alamouti space-time codes, and a convenient prefiltering at the terrestrial transmitter.

%B 2012 6th Advanced Satellite Multimedia Systems Conference (ASMS) and 12th Signal Processing for Space Communications Workshop (SPSC) (ASMS/SPSC 2012) %C Baiona, Spain %G eng %R 10.1109/ASMS-SPSC.2012.6333071 %0 Thesis %D 2012 %T Encrypted Domain Processing for Signal Processing Applications %A Juan Ramón Troncoso-Pastoriza %I University of Vigo %C Vigo %8 04/2012 %G eng %0 Conference Paper %B IEEE International Workshop on Information Forensics and Security (WIFS) %D 2012 %T Fingerprinting a flow of messages to an anonymous server. %A Juan A. Elices %A Fernando Pérez-González %B IEEE International Workshop on Information Forensics and Security (WIFS) %C Tenerife, Spain %P 97–102 %8 12/2012 %G eng %0 Conference Paper %B IEEE International Conference on Image Processing (ICIP) %D 2012 %T Fully Homomorphic Faces %A Juan Ramón Troncoso-Pastoriza %A Fernando Pérez-González %K face verification %K homomorphic processing %K lattice cryptography %K privacy %K watermarking %B IEEE International Conference on Image Processing (ICIP) %I IEEE %C Lake Buena Vista, Florida, USA %8 10/2012 %G eng %0 Conference Paper %B IEEE Int. Conf. on Acoustics, Speech and Signal Processing (ICASSP 2012) %D 2012 %T Generalized matched filter detector for fast fading channels %A Daniel Romero %A R. López-Valcarce %A Geert Leus %K cognitive radio %K dynacs %K spectrum sensing %XWe consider the problem of detecting a known signal with constant magnitude immersed in noise of unknown variance,

when the propagation channel is frequency-flat and randomly

time-varying within the observation window. A Basis Expansion

Model with random coefficients is used for the channel, and a Generalized Likelihood Ratio approach is adopted in order to cope with deterministic nuisance parameters. The resulting scheme can be seen as a generalization of the well-known

Matched Filter detector, to which it reduces for timeinvariant

channels. Closed-form analytical expressions are provided for the distribution of the test statistic under both hypotheses, which allow to assess the detection performance.

%B IEEE Int. Conf. on Acoustics, Speech and Signal Processing (ICASSP 2012)
%I IEEE
%C Kyoto, Japan
%8 07/2012
%G eng
%R 10.1109/ICASSP.2012.6288587
%0 Conference Paper
%B IEEE Workshop on Information Forensics and Security
%D 2012
%T IPTV streaming source classification
%A Miguel Masciopinto
%A Pedro Comesaña
%B IEEE Workshop on Information Forensics and Security
%C Tenerife, Spain
%G eng
%0 Conference Paper
%B IEEE International Workshop on Information Forensics and Security (WIFS)
%D 2012
%T A Least Squares approach to user profiling in pool mix-based anonymous communication systems.
%A Fernando Pérez-González
%A Carmela Troncoso
%B IEEE International Workshop on Information Forensics and Security (WIFS)
%C Tenerife, Spain
%P 115–120
%8 12/2012
%G eng
%0 Conference Paper
%B IEEE International Workshop on Information Forensics and Security (WIFS)
%D 2012
%T ML Estimation of the Resampling Factor
%A David Vázquez-Padín
%A Pedro Comesaña
%X In this work, the problem of resampling factor estimation for tampering detection is addressed following the maximum likelihood criterion. By relying on the rounding operation applied after resampling, an approximation of the likelihood function of the quantized resampled signal is obtained. From the underlying statistical model, the maximum likelihood estimate is derived for one-dimensional signals and a piecewise linear interpolation. The performance of the obtained estimator is evaluated, showing that it outperforms state-of-the-art methods.

%B IEEE International Workshop on Information Forensics and Security (WIFS) %I IEEE %C Tenerife, Spain %P 205-210 %8 12/2012 %G eng %0 Journal Article %J IEEE Trans. on Signal Processing %D 2012 %T Multiantenna GLR detection of rank-one signals with known power spectrum in white noise with unknown spatial correlation %A Josep Sala %A Gonzalo Vázquez-Vilar %A R. López-Valcarce %K cognitive radio %K dynacs %XMultiple-antenna detection of a Gaussian signal with spatial rank one in temporally white Gaussian noise with arbitrary and unknown spatial covariance is considered. This is motivated by spectrum sensing problems in the context of Dynamic Spectrum Access in which several secondary networks coexist but do not cooperate, creating a background of spatially correlated broadband interference. When the temporal correlation of the signal of interest is assumed known up to a scale factor, the corresponding Generalized Likelihood Ratio Test is shown to yield a scalar optimization problem. Closed-form expressions of the test are obtained for the general signal spectrum case in the low signal-to-noise ratio (SNR) regime, as well as for signals with binary-valued power spectrum in arbitrary SNR. The two resulting detectors turn out to be equivalent. An asymptotic approximation to the test distribution for the low-SNR regime is derived, closely matching empirical results from spectrum sensing simulation experiments.

%B IEEE Trans. on Signal Processing
%V 60
%P 3065 - 3078
%8 06/2012
%G eng
%N 6
%R 10.1109/TSP.2012.2189767
%0 Conference Paper
%B International Workshop on Digital-forensics and Watermarking
%D 2012
%T Multimedia operator chain topology and ordering estimation based on detection and information theoretic tools
%A Pedro Comesaña
%A Fernando Pérez-González
%B International Workshop on Digital-forensics and Watermarking
%C Shanghai, China
%G eng
%0 Conference Paper
%B ASILOMAR 2012
%D 2012
%T Multiuser Detection Performance in Multibeam Satellite Links under Imperfect CSI
%A Arnau, Jesus
%A C. Mosquera
%K dynacs
%K satcom
%B ASILOMAR 2012
%C Pacific Grove, CA
%G eng
%1 Accepted for publication

%R 10.1109/ACSSC.2012.6489048
%0 Conference Paper
%B Asilomar Conference on Signals, Systems, and Computers
%D 2012
%T Optimum Training for CSI Acquisition in Cognitive Radio Channels
%A Alberto Rico-Alvariño
%A C. Mosquera
%K adaptive signal processing
%K cognitive radio
%K dynacs
%B Asilomar Conference on Signals, Systems, and Computers
%C Pacific Grove, CA
%G eng
%R 10.1109/ACSSC.2012.6488973
%0 Journal Article
%J IEEE Transactions on Wireless Communications
%D 2012
%T Overlay Cognitive Transmission in a Multicarrier Broadcast Network with Dominant Line of Sight Reception
%A Alberto Rico-Alvariño
%A C. Mosquera
%A Fernando Pérez-González
%K cognitive radio
%K dynacs
%K satcom
%B IEEE Transactions on Wireless Communications
%G eng
%R 10.1109/TWC.2012.092112.120257
%0 Conference Paper
%B 3rd International Workshop on Cognitive Information Processing (CIP)
%D 2012
%T Overlay cognitive transmission in OFDM point to point systems exploiting primary feedback
%A Alberto Rico-Alvariño
%A C. Mosquera
%K cognitive radio
%K dynacs
%X A secondary user that tries to reuse the spectrum allocated to a primary user can exploit the knowledge of the primary message to perform this task. In particular, the overlay cognitive radio paradigm postulates the use of a fraction of the available power at the secondary transmitter to convey the primary message, so the spectral efficiency of the primary system is increased, and, therefore, some transmission resources (time slots or frequency bands) can be released to the secondary transmission while the primary user rate is kept constant. The fraction of released resources can be incremented if some channel state information is available at the secondary transmitter. In this paper, we present a scenario where the secondary transmitter maximizes the primary link quality (measured in terms of Effective SNR), and obtains its channel state information by exploiting the primary user SNR-based feedback.

%B 3rd International Workshop on Cognitive Information Processing (CIP) %C Baiona, Galicia, Spain %8 05/2012 %G eng %R 10.1109/CIP.2012.6232932 %0 Conference Proceedings %B IEEE Symposium on New Frontiers in Dynamic Spectrum Access Networks (DySPAN 2012) %D 2012 %T Overlay Spectrum Reuse in a Broadcast Network: Covering the Whole Grayscale of Spaces %A Alberto Rico-Alvariño %A C. Mosquera %K cognitive radio %K dynacs %B IEEE Symposium on New Frontiers in Dynamic Spectrum Access Networks (DySPAN 2012) %C Bellevue, WA %G eng %R 10.1109/DYSPAN.2012.6478172 %0 Conference Paper %B The 13th IEEE International Workshop on Signal Processing Advances in Wireless Communications (SPAWC 2012) %D 2012 %T Overlay Spectrum Reuse in a Multicarrier Broadcast Network: Coverage Analysis %A Alberto Rico-Alvariño %A C. Mosquera %A Fernando Pérez-González %K cognitive radio %K dynacs %XA secondary cognitive user overlaying its message in a broadcast multicarrier network is studied. The secondary user exploits the primary message knowledge to convey its own information while preserving the primary user coverage area, determined by a bound on the BER, and taking into account the degradation due to the insertion of an echo in a dominant line of sight environment. The results are compared with those obtained when the coverage area is defined in capacity terms, and regardless of the degradation caused by the secondary replica of the primary message.

%B The 13th IEEE International Workshop on Signal Processing Advances in Wireless Communications (SPAWC 2012) %C Cesme, Turkey %G eng %R 10.1109/SPAWC.2012.6292889 %0 Conference Paper %B The 13th IEEE International Workshop on Signal Processing Advances in Wireless Communications (SPAWC 2012) %D 2012 %T Overlay Spectrum Reuse in a Multicarrier Broadcast Network: Single Receiver Analysis %A Alberto Rico-Alvariño %A C. Mosquera %A Fernando Pérez-González %K cognitive radio %K dynacs %XThe overlay cognitive radio paradigm presents a framework where a secondary user exploits the knowledge of the primary user's message to improve spectrum utilization. A multicarrier broadcast network is one of the scenarios where this knowledge is possible: the secondary user could join a single frequency network and, therefore, gain access to the primary message. However, if the primary signal is received with a strong line of sight component, its relaying from the secondary transmitter does not suffice to ensure the primary user quality of service. In this paper we study the scenario where a secondary transmitter maximizes its own transmission rate, keeping the quality of a primary receiver over a given threshold. The analytical results, based on bit error rate bounds, are verified by means of software simulations and hardware tests.

%B The 13th IEEE International Workshop on Signal Processing Advances in Wireless Communications (SPAWC 2012) %C Cesme, Turkey %G eng %R 10.1109/SPAWC.2012.6292890 %0 Conference Paper %B 2012 6th Advanced Satellite Multimedia Systems Conference (ASMS) and 12th Signal Processing for Space Communications Workshop (SPSC) (ASMS/SPSC 2012) %D 2012 %T Performance Analysis of Multiuser Detection for Multibeam Satellites Under Rain Fading %A Arnau, Jesus %A C. Mosquera %K dynacs %K hybrid beamforming %K multibeam satellites. %K Multiuser detection %K rain fading %K satcom %XMultibeam satellite systems are nowadays widely employed, and their use is expected to grow in the next decades. This has raised the interest for signal processing techniques able to mitigate the interference among beams, since they could enable a much more aggressive spectrum reuse. From an engineering point of view, the design of the system must be no longer based on the capabilities provided by the usual physical layer; it should take into account the presence of these interference canceling techniques, predict their performance as accurately as possible -even under a number of impairments and non-idealities- and design accordingly in order to fully exploit them. In this paper, we investigate the effect of a practical impairment of great importance, namely, the attenuation due to the rain, on the performance of a return link which performs MMSE interference canceling. Analytical expressions are derived for a number of performance measures based on the statistical characterization of the rain attenuation.

%B 2012 6th Advanced Satellite Multimedia Systems Conference (ASMS) and 12th Signal Processing for Space Communications Workshop (SPSC) (ASMS/SPSC 2012) %C Baiona, Spain %G eng %R 10.1109/ASMS-SPSC.2012.6333078 %0 Journal Article %J EURASIP Journal on Wireless Communications and Networking %D 2012 %T Performance study of multiuser interference mitigation schemes for hybrid broadband multibeam satellite architectures %A Arnau, Jesus %A Bertrand Devillers %A C. Mosquera %A Ana Pérez-Neira %B EURASIP Journal on Wireless Communications and Networking %V 2012 %P 132 %G eng %U http://jwcn.eurasipjournals.com/content/2012/1/132 %R 10.1186/1687-1499-2012-132 %0 Conference Paper %B Privacy Enhancing Technologies Symposium (PETS) %D 2012 %T Understanding statistical disclosure: A least squares approach %A Fernando Pérez-González %A Carmela Troncoso %B Privacy Enhancing Technologies Symposium (PETS) %C Vigo, Spain %P 38–57 %8 07/2012 %G eng %0 Conference Paper %B IEEE International Conference on Intelligent Systems Design and Applications (ISDA) %D 2011 %T On the Application of a Hybrid Harmony Search Algorithm to Node Localization in Anchor-based Wireless Sensor Networks %A Diana Manjarres %A Javier Del Ser %A Sergio Gil-Lopez %A Massimo Vecchio %A Itziar Landa-Torres %A R. López-Valcarce %B IEEE International Conference on Intelligent Systems Design and Applications (ISDA) %G eng %0 Conference Paper %B International Workshop on Computational Advances in Multi-Sensor Adaptive Processing (CAMSAP) %D 2011 %T Bandlimited or Constant Envelope? Exploiting Waveform Properties in Wireless Microphone Detection %A Daniel Romero %A R. López-Valcarce %K Bandlimited signals. %K Constant Magnitude %K dynamic spectrum access %K Wireless Microphones %B International Workshop on Computational Advances in Multi-Sensor Adaptive Processing (CAMSAP) %C San Juan, Puerto Rico %P 17-20 %8 December %G eng %0 Journal Article %J Vehicular Technology, IEEE Transactions on %D 2011 %T Bit Loading Using Imperfect CSIT for Prediction-Based Resource Allocation in Mobile OFDMA %A Schmidt, J.F. %A Cousseau, J.E. %A Wichman, R. %A Werner, S. %K bit loading %K channel state information in the transmitter %K CSIT %K frequency division multiple access %K imperfect channel prediction information %K mobile OFDMA %K mobile radio %K mobile stations %K OFDM modulation %K orthogonal frequency division multiple access %K prediction error %K prediction-based resource allocation %K radio transmitters %K time-varying channels %K wireless channel %B Vehicular Technology, IEEE Transactions on %V 60 %P 4082 -4088 %8 oct. %G eng %R 10.1109/TVT.2011.2165305 %0 Conference Paper %B International Conference on Cognitive Radio and Advanced Spectrum Management %D 2011 %T On the Co-existence of Primary and Secondary Transmitters in a Broadcast Network %A Alberto Rico-Alvariño %A C. Mosquera %A Fernando Pérez-González %K Broadcast %K cognitive radio %K Overlay %K Single Frequency Network %B International Conference on Cognitive Radio and Advanced Spectrum Management %C Barcelona, Catalonia, Spain %G eng %0 Conference Paper %B IEEE Int. Conf. on Acoustics, Speech and Signal Processing (ICASSP 2011) %D 2011 %T Detection diversity of multiantenna spectrum sensors %A Gonzalo Vázquez-Vilar %A R. López-Valcarce %A Ashish Pandharipande %K cognitive radio %K detection diversity %K spectrum sensing %XIn the context of spectrum sensing, we investigate the performance of detectors equipped with M antennas (co-located or distributed) under Rayleigh fading, in terms of detection diversity. Rather than the high-SNR concept of diversity order common in the communications literature, we adopt the notion recently advocated by Daher and Adve in the radar community: the slope of the average probability of detection (\bar{P}_D) vs. SNR curve at \bar{P}_D = 0.5. This definition is well suited to spectrum sensing, which invariably deals with low SNR levels. It is shown that the diversity order grows as M for an optimal centralized detector having access to all observations, whereas for the two distributed schemes considered (the multiantenna energy detector and the OR detector) it grows no faster than √M.

%B IEEE Int. Conf. on Acoustics, Speech and Signal Processing (ICASSP 2011)
%I IEEE
%C Prague, Czech Republic
%P 2936-2939
%8 05/2011
%G eng
%0 Journal Article
%J IEEE Trans. on Signal Processing
%D 2011
%T Detection of Rank-P Signals in Cognitive Radio Networks With Uncalibrated Multiple Antennas
%A David Ramírez
%A Gonzalo Vázquez-Vilar
%A R. López-Valcarce
%A Javier Vía
%A Ignacio Santamaría
%K cognitive radio
%K dynacs
%K spectrum sensing
%X Spectrum sensing is a key component of the Cognitive Radio paradigm. Typically, primary signals have to be detected with uncalibrated receivers at signal-to-noise ratios (SNRs) well below decodability levels. Multiantenna detectors exploit spatial independence of receiver thermal noise to boost detection performance and robustness. We study the problem

of detecting a Gaussian signal with rank-P unknown spatial

covariance matrix in spatially uncorrelated Gaussian noise with

unknown covariance using multiple antennas. The generalized

likelihood ratio test (GLRT) is derived for two scenarios. In the

first one, the noises at all antennas are assumed to have the same (unknown) variance, whereas in the second, a generic diagonal noise covariance matrix is allowed in order to accommodate calibration uncertainties in the different antenna frontends. In the latter case, the GLRT statistic must be obtained numerically, for which an efficient method is presented. Furthermore, for asymptotically low SNR, it is shown that the GLRT does admit a closed form, and the resulting detector performs well in practice. Extensions are presented in order to account for unknown temporal correlation in both signal and noise, as well as frequency-selective channels.

%B IEEE Trans. on Signal Processing
%V 59
%P 3764-3774
%8 08/2012
%G eng
%N 8
%R 10.1109/TSP.2011.2146779
%0 Conference Paper
%B IEEE International Conference on Communications (ICC)
%D 2011
%T A Dirty Paper Scheme for Hierarchical OFDM
%A Scagliola, Michele
%A Fernando Pérez-González
%A Guccione, Pietro
%K dirty paper
%K Hierarchical OFDM
%K watermarking
%B IEEE International Conference on Communications (ICC)
%C Kioto, Japan
%8 June
%G eng
%0 Conference Paper
%B IEEE Workshop on Signal Processing Advances in Wireless Communications (SPAWC)
%D 2011
%T Distributed spectrum sensing with multiantenna sensors under calibration errors
%A Daniel Romero
%A R. López-Valcarce
%K ad hoc detectors
%K antenna arrays
%K calibration
%K calibration errors
%K cognitive radio
%K energy detector
%K generalized likelihood ratio
%K log normal distribution
%K lognormal shadowing
%K multiantenna sensors
%K Ricean fading
%K spectrum sensing
%K wireless medium
%X Spectrum sensing design for Cognitive Radio systems is challenged by the nature of the wireless medium, which makes the detection requirements difficult to achieve by standalone sensors. To combat shadowing and fading, distributed strategies are usually proposed. However, most distributed approaches are based on the energy detector, which is not robust to noise uncertainty. This phenomenon can be overcome by multi-antenna sensors exploiting spatial independence of the noise process. We combine both ideas to develop distributed detectors for multiantenna sensors. Fusion rules are provided for sensors based on the Generalized Likelihood Ratio as well as for ad hoc detectors derived from geometric considerations. Simulation results are provided comparing the performance of the different strategies under lognormal shadowing and Ricean fading.

%B IEEE Workshop on Signal Processing Advances in Wireless Communications (SPAWC) %P 441 -445 %8 june %G eng %R 10.1109/SPAWC.2011.5990448 %0 Conference Paper %B IEEE International Conference on Mobile Ad-hoc and Sensor Systems (MASS) %D 2011 %T An Effective Metaheuristic Approach to Node Localization in Wireless Sensor Networks %A Massimo Vecchio %A R. López-Valcarce %A Francesco Marcelloni %B IEEE International Conference on Mobile Ad-hoc and Sensor Systems (MASS) %G eng %0 Conference Paper %B IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) %D 2011 %T Efficient Protocols for Secure Adaptive Filtering %A Juan Ramón Troncoso-Pastoriza %A Fernando Pérez-González %K adaptive filtering %K privacy %K security %K watermarking %B IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) %I IEEE %C Prage, Czech Republic %P 5860-5863 %8 May %G eng %0 Conference Paper %B International Conference on Cloud Computing and Services Science (CLOSER) %D 2011 %T Encrypted Domain Processing for Cloud Privacy: Concept and Practical Experience %A Daniel A. Rodríguez-Silva %A F. Javier González-Castaño %A Lilian Adkinson-Orellana %A Alexandre Fernández-Cordeiro %A Juan Ramón Troncoso-Pastoriza %A Daniel González-Martínez %K cloud %K privacy %K security %K watermarking %B International Conference on Cloud Computing and Services Science (CLOSER) %C Noordwijkerhout, The Netherlands %8 May %G eng %0 Conference Paper %B International Workshop on Digital Watermarking (IWDW) %D 2011 %T Exposing original and duplicated regions using SIFT features and resampling traces %A David Vázquez-Padín %A Fernando Pérez-González %K Image forensics %K region duplication %K resampling estimation %K SIFT %XA common type of digital image forgery is the duplication of a region in the same image to conceal something in a captured scene. The detection of region duplication forgeries has been recently addressed using methods based on SIFT features that provide points of the regions involved in the tampering and also the parameters of the geometric transformation between both regions. However, considering this output, there is not yet any information about which of the regions are originals and which are the duplicated ones. A reliable image forensic analysis must provide this information. In this paper, we propose to use a resampling-based method to provide an accurate way to distinguish the original and the tampered regions by analizing the resampling factor of each area. Comparative results are presented to evaluate the performance of the combination of both methods.

%B International Workshop on Digital Watermarking (IWDW) %I Springer Berlin Heidelberg %C Atlantic City, USA %P 306-320 %8 10/2011 %G eng %R 10.1007/978-3-642-32205-1_25 %0 Journal Article %J IEEE Transactions on Communications %D 2011 %T Gain-Invariant Dirty Paper Coding for Hierarchical OFDM %A Scagliola, Michele %A Fernando Pérez-González %A Guccione, Pietro %K dirty paper %K dynacs %K Hierarchical OFDM %K watermarking %X

A novel approach is here presented to superimpose a low-priority data stream on a high-priority data stream for OFDM systems. The main improvement with respect to conventional hierarchical modulation, which is included with the same purpose in various wireless technologies, is that the low-priority data stream can be decoded from the received subcarrier symbols without any previous equalization for multipath fading channels. As a consequence, the expected performance is nearly invariant of the channel estimation method used to equalize the channel. The low-priority stream is inserted adopting a gain-invariant dirty paper coding based on Rational Dither Modulation, which was proposed for data hiding applications. In this paper an analysis of the developed system is presented and several simulations have been carried out using DVB-T system parameters to verify the validity of the proposed approach. The experimental results show the better performance of the proposed method with respect to that of a conventional hierarchical modulation, particularly when the accuracy of the estimated channel response decreases.

%B IEEE Transactions on Communications %V 59 %P 3323-3334 %8 December %G eng %R 10.1109/TCOMM.2011.101011.100544 %0 Conference Paper %B IEEE GLOBECOM %D 2011 %T Hybrid Space-Ground Processing for High-Capacity Multi-beam Satellite Systems %A Arnau, Jesus %A Michael Bergmann %A Enzo Alberto Candreva %A Giovanni Emanuele Corazza %A Riccardo {De Gaudenzi} %A Bertrand Devillers %A Wilfried Gappmair %A Francesco Lombardo %A C. Mosquera %A Ana Pérez-Neira %A Ilaria Thibault %A Alessandro Vanelli-Coralli %B IEEE GLOBECOM %C Houston, Texas, USA %8 dec %G eng %0 Conference Paper %B IEEE International Conference on Multimedia and Expo (ICME) %D 2011 %T Improving the Visual Performance of S/DISCUS %A Gabriel Domínguez-Conde %A Deepa Kundur %K distributed source coding %K keyless security %K low-complexity video coding %K Slepian-Wolf coding %K watermarking %K wireless multimedia sensor networks %B IEEE International Conference on Multimedia and Expo (ICME) %C Barcelona, Catalonia %8 July %G eng %0 Thesis %D 2011 %T Interference and Network Management in Cognitive Communication Systems %A Gonzalo Vázquez-Vilar %K cognitive radio %K spectrum sensing %I University of Vigo %C Vigo, Spain %V Ph.D. %8 06/2011 %G eng %9 Ph.D. thesis %0 Conference Paper %B IEEE GLOBECOM %D 2011 %T Joint Linear Precoding and Beamforming for the Forward Link of Multi-Beam Broadband Satellite Systems %A Bertrand Devillers %A Ana Isabel Perez %A C. Mosquera %B IEEE GLOBECOM %C Houston, Texas, USA %G eng %0 Journal Article %J Circuits and Systems I: Regular Papers, IEEE Transactions on %D 2011 %T Low-Complexity Channel Prediction Using Approximated Recursive DCT %A Schmidt, J.F. %A Cousseau, J.E. %A Wichman, R. %A Werner, S. %K autoregressive modeling %K autoregressive processes %K basis expansion model %K channel estimator %K computational complexity %K DCT %K discrete cosine transform %K discrete cosine transforms %K Doppler frequencies %K filter bank %K Kalman filters %K low-complexity channel prediction %K OFDM modulation %K OFDM systems %K recursive formulation %K steady-state Kalman filter %K sum-of-sinusoids channel predictors %K time-varying channels %B Circuits and Systems I: Regular Papers, IEEE Transactions on %V 58 %P 2520 -2530 %8 oct. %G eng %R 10.1109/TCSI.2011.2158139 %0 Conference Paper %B IEEE Workshop on Signal Processing Advances in Wireless Communications (SPAWC) %D 2011 %T Multiantenna detection of constant-envelope signals in noise of unknown variance %A Daniel Romero %A R. López-Valcarce %K cognitive radio %K multiantenna detection %K spectrum sensing %XDetection of unknown signals with constant modulus (CM) using multiple antennas in additive white Gaussian noise of unknown variance is considered. The channels from the source to each antenna are assumed frequency-flat and unknown. This problem is of interest for spectrum sensing in cognitive radio systems in which primary signals are known to have the CM property. Examples include analog frequency modulated signals such as those transmitted by wireless microphones in the TV bands and Gaussian Minimum Shift Keying modulated signals as in the GSM cellular standard. The proposed detector, derived from a Generalized Likelihood Ratio (GLR) approach, exploits both the CM property and the spatial independence of noise, outperforming the GLR test for Gaussian signals as shown by simulation.

%B IEEE Workshop on Signal Processing Advances in Wireless Communications (SPAWC) %P 446 -450 %8 june %G eng %R 10.1109/SPAWC.2011.5990449 %0 Conference Paper %B IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) %D 2011 %T Multiantenna detection under noise uncertainty and primary user's spatial structure %A David Ramírez %A Gonzalo Vázquez-Vilar %A R. López-Valcarce %A Javier Vía %A Ignacio Santamaría %K cognitive radio %K generalized likelihood ratio test (GLRT) %K spectrum sensing %B IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) %I IEEE %C Prage, Czech Republic %P 2948-2951 %8 May %G eng %0 Journal Article %J IEEE Trans. on Wireless Communications %D 2011 %T Multiantenna Spectrum Sensing Exploiting Spectral a priori Information %A Gonzalo Vázquez-Vilar %A R. López-Valcarce %A Josep Sala %K cognitive radio %K dynacs %K spectrum sensing %B IEEE Trans. on Wireless Communications %V 10 %P 4345 - 4355 %8 12/2011 %G eng %N 12 %R 10.1109/TWC.2011.101211.110665 %0 Conference Paper %B Document Recognition and Retrieval %D 2011 %T A new method for perspective correction of document images %A José Rodríguez-Piñeiro %A Pedro Comesaña %A Fernando Pérez-González %A Alberto Malvido %K Document image %K perspective distortion correction %K watermarking %B Document Recognition and Retrieval %S Proc. of SPIE %I SPIE %C San Francisco, CA %V 7874 %P 787410 %8 January %G eng %0 Conference Paper %B Information Sciences and Systems (CISS), 2011 45th Annual Conference on %D 2011 %T Prediction based resource allocation in OFDMA %A Schmidt, J.F. %A Cousseau, J.E. %A Wichman, R. %A Werner, S. %K empirical characterization %K frequency division multiple access %K low-complexity channel predictor %K mobile radio %K mobile stations %K mobile wireless channels %K OFDM modulation %K OFDMA downlink %K orthogonal frequency division multiple access downlink %K perfect channel state information %K prediction error characterization %K prediction-based RA strategies %K prediction-based resource allocation algorithm %K wireless channels %B Information Sciences and Systems (CISS), 2011 45th Annual Conference on %P 1 -4 %8 march %G eng %R 10.1109/CISS.2011.5766224 %0 Conference Paper %B IEEE International Workshop on Information Forensics and Security (WIFS) %D 2011 %T Prefilter Design for Forensic Resampling Estimation %A David Vázquez-Padín %A Fernando Pérez-González %XStarting from a theoretical analysis of the resampling estimation problem for image tampering detection, this work presents a study, based on cyclostationarity theory, about the use of prefilters to improve the estimation accuracy of the resampling factor. Considering the methods that perform the estimation by analyzing the spectrum of the covariance of a resampled region, we propose an analytical framework that allows the definition of a cost function that measures the degree of detectability of the spectral peaks. Based on this measure, the design of the optimum prefilters for a particular resampling factor can be solved numerically. Experimental results validate the developed analysis and illustrate the enhancement of the performance in a real scenario.

%B IEEE International Workshop on Information Forensics and Security (WIFS) %I IEEE %C Foz do Iguaçu, Brazil %P 1-6 %8 12/2011 %G eng %R 10.1109/WIFS.2011.6123133 %0 Journal Article %J IEEE Transactions on Information Forensics and Security %D 2011 %T Secure Adaptive Filtering %A Juan Ramón Troncoso-Pastoriza %A Fernando Pérez-González %K adaptive signal processing %K computational complexity %K cryptography %K digital data protection %K encrypted domain %K homomorphic encryption systems %K least mean squares algorithm %K least mean squares methods %K privacy %K secure adaptive filtering %K security %K signal privacy preservation %K SPED techniques %K watermarking %B IEEE Transactions on Information Forensics and Security %V 6 %P 469 -485 %8 June %G eng %R 10.1109/TIFS.2011.2109385 %0 Conference Paper %B the 3-th IEEE World Congress on Nature and Biologically Inspired Computing (NaBIC 2011) %D 2011 %T Solving the Node Localization Problem in WSNs by a Two-objective Evolutionary Algorithm and Gradient Descent %A Massimo Vecchio %A R. López-Valcarce %A Francesco Marcelloni %B the 3-th IEEE World Congress on Nature and Biologically Inspired Computing (NaBIC 2011) %G eng %0 Journal Article %J IEEE Trans. on Signal Processing %D 2011 %T Spectrum Sensing Exploiting Guard Bands and Weak Channels %A Gonzalo Vázquez-Vilar %A R. López-Valcarce %K cognitive radio %K dynacs %K spectrum sensing %XWe address the problem of primary user detection in Cognitive Radio from a wideband signal comprising multiple primary channels, exploiting a priori knowledge about the primary network: channelization and spectral shape of primary transmissions. Using this second-order statistical information, a multichannel Gaussian model is formulated. In order to obtain a Generalized Likelihood Ratio Test, we first address Maximum Likelihood (ML) estimation of the power levels at the different channels, as well as of the noise variance. The ML conditions suggest a suboptimal closed-form estimate, which takes the form of a constrained Least Squares estimator whose asymptotic efficiency is shown for flat bandpass spectra in white noise, a case of practical importance. The resulting detectors exploit those frequency bins corresponding to guard bands and to primary channels perceived as weak to improve noise variance estimation. Analytical expressions for the probabilities of detection and false alarm are presented. Performance is evaluated via simulations in the setting of a terrestrial TV primary network with realistic channelization parameters.

%B IEEE Trans. on Signal Processing
%V 59
%P 6045-6057
%8 12/2011
%G eng
%N 12
%R 10.1109/TSP.2011.2167615
%0 Conference Paper
%B IEEE International Conference on Intelligent Systems Design and Applications (ISDA)
%D 2011
%T A study on the Application of Different Two-objective Evolutionary Algorithms to the Node Localization Problem in Wireless Sensor Networks
%A Massimo Vecchio
%A R. López-Valcarce
%A Francesco Marcelloni
%B IEEE International Conference on Intelligent Systems Design and Applications (ISDA)
%G eng
%0 Journal Article
%J Applied Soft Computing
%D 2011
%T A two-objective evolutionary approach based on topological constraints for node localization in wireless sensor networks
%A Massimo Vecchio
%A R. López-Valcarce
%A Francesco Marcelloni
%K dynacs
%K Multiobjective evolutionary algorithms
%K Node localization
%K Range measurements
%K Stochastic optimization
%K wsn
%X To know the location of nodes plays an important role in many current and envisioned wireless sensor network applications. In this framework, we consider the problem of estimating the locations of all the nodes of a network, based on noisy distance measurements for those pairs of nodes in range of each other, and on a small fraction of anchor nodes whose actual positions are known a priori. The methods proposed so far in the literature for tackling this non-convex problem do not generally provide accurate estimates. The difficulty of the localization task is exacerbated by the fact that the network is not generally uniquely localizable when its connectivity is not sufficiently high. In order to alleviate this drawback, we propose a two-objective evolutionary algorithm which takes concurrently into account during the evolutionary process both the localization accuracy and certain topological constraints induced by connectivity considerations. The proposed method is tested with different network configurations and sensor setups, and compared in terms of normalized localization error with another metaheuristic approach, namely SAL, based on simulated annealing. The results show that, in all the experiments, our approach achieves considerable accuracies and significantly outperforms SAL, thus manifesting its effectiveness and stability.

%B Applied Soft Computing %V 12 %P 1891-1901 %8 07/2012 %G eng %N 7 %R 10.1016/j.asoc.2011.03.012 %0 Conference Paper %B IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) %D 2011 %T Weber's law-based side-informed data hiding %A Pedro Comesaña %A Fernando Pérez-González %K data hiding %K Logarithmic watermarking %K Perceptually shaped watermarks %K watermarking %K Weber's law %B IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) %C Prague, Czech Republic %P 1840-1843 %8 May %G eng %0 Conference Paper %B International Workshop on Digital Watermarking (IWDW) %D 2011 %T Witsenhausen's counterexample and its links with multimedia security problems %A Pedro Comesaña %A Fernando Pérez-González %A Chaouki T. Abdallah %K control %K Multimedia security %K Witsenhausen's counterexample %B International Workshop on Digital Watermarking (IWDW) %C Atlantic City, USA %8 October %G eng %0 Journal Article %J IEEE Transactions on Information Theory %D 2010 %T Asymptotically Optimum Universal Watermark Embedding and Detection in the High-SNR Regime %A Pedro Comesaña %A Neri Merhav %A Mauro Barni %K hypothesis testing %K Neyman-Pearson %K watermark detection %K watermark embedding %K watermarking %B IEEE Transactions on Information Theory %V 56 %P 2804-2815 %8 June %G eng %0 Journal Article %J Signal Processing %D 2010 %T Blind l_1-Norm-Based Phase Estimation for Cross-QAM Robust to Finite Precision Effects %A Marcos Álvarez-Díaz %A R. López-Valcarce %A Iago Gómez-Alonso %K blind phase estimation %K carrier offset %K cross-QAM constellations %K fixed point implementation %B Signal Processing %V 90 %P 2934-2948 %8 11/2010 %G eng %0 Journal Article %J Signal Processing %D 2010 %T Closed-form real single-tone frequency estimator based on a normalized IIR notch filter %A R. Elasmi-Ksibi %A S. Cherif %A R. López-Valcarce %A H. Besbes %K Frequency estimation %K IIR notchfilter %K Least squares %K Real sinusoid %K RPHD estimator %B Signal Processing %V 90 %P 1905-1915 %8 June %G eng %0 Conference Paper %B International Workshop on Cloud Information System Engineering (CISE) %D 2010 %T CryptoDSPs for Cloud Privacy %A Juan Ramón Troncoso-Pastoriza %A Fernando Pérez-González %K cloud %K privacy %K security %K watermarking %B International Workshop on Cloud Information System Engineering (CISE) %S LNCS %C Hong Kong, China %V 6724 %8 December %G eng %0 Thesis %D 2010 %T Design of Nonlinear Precoding and Estimation Schemes for Advanced Communication Systems %A Marcos Álvarez-Díaz %K adaptive signal processing %K satcom %V Ph.D. %8 04/2010 %G eng %9 Ph.D. thesis %0 Journal Article %J IEEE Transactions on Vehicular Technology %D 2010 %T Dynamic spectrum leasing (DSL): A new paradigm for spectrum sharing in cognitive radio networks %A Sudhaman K. Jayaweera %A Gonzalo Vázquez-Vilar %A C. Mosquera %K cognitive radio %K DSL %K dynamic spectrum access %K dynamic spectrum leasing %K dynamic spectrum sharing %K game theory %K power control %B IEEE Transactions on Vehicular Technology %V 59 %P 2328-2339 %G eng %0 Conference Paper %B ICC Workshop on Cognitive Radio Interfaces and Signal Processing (ICC CRISP) %D 2010 %T Dynamic Spectrum Leasing (DSL) in Dynamic Channels %A Georges El-Howayek %A Sudhaman K. Jayaweera %A Kamrul Hakim %A Gonzalo Vázquez-Vilar %A C. Mosquera %K cognitive radio %K DSL %K dynamic spectrum leasing %K game theory %K Rayleigh fading %K time-varying channels %K time-varying secondary system %B ICC Workshop on Cognitive Radio Interfaces and Signal Processing (ICC CRISP) %C Cape Town, South Africa %8 May 23 %G eng %0 Journal Article %J IEEE Transactions on Wireless Communications %D 2010 %T Efficient Dynamic Spectrum Sharing in Cognitive Radio Networks: Centralized Dynamic Spectrum Leasing (C-DSL) %A Kamrul Hakim %A Sudhaman K. Jayaweera %A Georges El-Howayek %A C. Mosquera %B IEEE Transactions on Wireless Communications %V 9 %P 2956-2967 %G eng %0 Conference Paper %B European Wireless %D 2010 %T A finite interval constant modulus criterion for multicarrier channel shortening %A E. Ben Salem %A R. López-Valcarce %A H. Besbes %A S. Cherif %B European Wireless %C Lucca, Italy %G eng %0 Journal Article %J Signal Processing %D 2010 %T Frequency estimation of real-valued single-tone in colored noise using multiple autocorrelation lags %A R. Elasmi-Ksibi %A H. Besbes %A R. López-Valcarce %A S. Cherif %K Autocorrelation %K Frequency estimation %K Single sinusoid %B Signal Processing %V 90 %P 2303-2307 %8 July %G eng %0 Journal Article %J IEEE Signal Processing Letters %D 2010 %T Joint NDA Estimation of Carrier Frequency/Phase and SNR for Linearly Modulated Signals %A Wilfried Gappmair %A R. López-Valcarce %A C. Mosquera %K Carrier offset estimation %K Cramer-Rao lower bound %K expectation-maximization algorithm %K SNR estimation %B IEEE Signal Processing Letters %V 17 %P 517-520 %8 05/2010 %G eng %0 Journal Article %J Digital Investigation %D 2010 %T Leaving Timing Channel Fingerprints in Hidden Service Log Files %A Bilal Shebaro %A Fernando Pérez-González %A Jedidiah R. Crandall %K data-hiding %K fingerprints %K hidden services %K timestamps %K timing channel %K tor network %K watermarking %B Digital Investigation %G eng %0 Conference Paper %B Digital Forensic Research Workshop Annual Conference (DFRWS) %D 2010 %T Leaving Timing Channel Fingerprints in Hidden Service Log Files %A Bilal Shebaro %A Fernando Pérez-González %A Jedidiah R. Crandall %K data hiding %K fingerprints %K hidden services %K timestamps %K timing channel %K tor network %K watermarking %B Digital Forensic Research Workshop Annual Conference (DFRWS) %C Portland, Oregon %8 August %G eng %0 Conference Paper %B IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) %D 2010 %T Multiantenna spectrum sensing: detection of spatial correlation among time-series with unknown spectra %A David Ramírez %A Javier Vía %A Ignacio Santamaría %A R. López-Valcarce %A L. L. Scharf %K cognitive radio %K coherence spectrum %K generalized likelihood ratio test %K Hadamard ratio %K multiple-channel signal detection %B IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) %C Dallas, TX %G eng %0 Conference Paper %B International Workshop on Cognitive Information Processing (CIP) %D 2010 %T Multiantenna spectrum sensing for Cognitive Radio: overcoming noise uncertainty %A R. López-Valcarce %A Gonzalo Vázquez-Vilar %A Josep Sala %B International Workshop on Cognitive Information Processing (CIP) %C Elba Island, Italy %G eng %0 Conference Paper %B IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) %D 2010 %T A new model for Gabor Coefficients' Magnitude in Face Recognition %A Juan Ramón Troncoso-Pastoriza %A Daniel González-Jiménez %A Fernando Pérez-González %K Gabor coefficients %K generalized Gaussian %K Magnitude %K Quantization %K Statistical Model %K watermarking %B IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) %I IEEE %C Dallas, USA %8 March %G eng %0 Conference Paper %B Advanced Satellite Multimedia Systems Conference (ASMA) %D 2010 %T Performance Analysis of Distributed Tracking with Consensus on Noisy Time-Varying Graphs %A Yongxiang Ruan %A Sudhaman K. Jayaweera %A C. Mosquera %K connectivity graph %K distributed local Kalman filtering %K distributed tracking %K distributed tracking with consensus %K graph topology %K network theory (graphs) %K noisy communications links %K noisy time-varying graphs %K performance analysis %K telecommunication links %K telecommunication network topology %K time-varying network topology %K time-varying systems %B Advanced Satellite Multimedia Systems Conference (ASMA) %C Cagliari, Italy %P 395-400 %G eng %0 Journal Article %J IEEE Transactions on Wireless Communications %D 2010 %T Primary User Enters the Game: Performance of Dynamic Spectrum Leasing in Cognitive Radio Networks %A Gonzalo Vázquez-Vilar %A C. Mosquera %A Sudhaman K. Jayaweera %B IEEE Transactions on Wireless Communications %G eng %0 Conference Paper %B IEEE International Conference on Image Processing (ICIP) %D 2010 %T On the Role of Differentiation for Resampling Detection %A Nahuel Dalgaard %A C. Mosquera %A Fernando Pérez-González %K cyclostationarity %K Image forensics %K interpolation %K prefiltering %K resampling detection %K watermarking %B IEEE International Conference on Image Processing (ICIP) %I IEEE %C Hong Kong, China %8 September %G eng %0 Conference Paper %B Virtual Physiological Human (VPH) %D 2010 %T Secure and Private Medical Clouds using Encrypted Processing %A Juan Ramón Troncoso-Pastoriza %A Fernando Pérez-González %K cloud %K privacy %K security %K watermarking %B Virtual Physiological Human (VPH) %C Brussels, Belgium %8 October %G eng %0 Journal Article %J IEEE Transactions on Signal Processing %D 2010 %T SNR Estimation for Multilevel Constellations Using Higher-Order Moments %A Marcos Álvarez-Díaz %A R. López-Valcarce %A C. Mosquera %K Blind estimation %K higher-order statistics %K Moments-based estimation %K SNR estimation %B IEEE Transactions on Signal Processing %V 58 %P 1515–1526 %8 March %G eng %0 Journal Article %J IEEE Signal Processing Letters %D 2010 %T Stepsize Sequence Design for Distributed Average Consensus %A C. Mosquera %A R. López-Valcarce %A Sudhaman K. Jayaweera %B IEEE Signal Processing Letters %V 17 %P 169-172 %8 Feb %G eng %0 Conference Paper %B IEEE International Conference on Image Processing (ICIP) %D 2010 %T Two-dimensional Statistical Test for the Presence of Almost Cyclostationarity on Images %A David Vázquez-Padín %A C. Mosquera %A Fernando Pérez-González %K cyclostationarity %K Image forensics %K interpolation %K resampling factor estimation %K spatial transformation %K watermarking %XIn this work, we study the presence of almost cyclostationary fields in images for the detection and estimation of digital forgeries. The almost periodically correlated fields in the two-dimensional space are introduced by the necessary interpolation operation associated with the applied spatial transformation. In this theoretical context, we extend a statistical time-domain test for presence of cyclostationarity to the two-dimensional space. The proposed method allows us to estimate the scaling factor and the rotation angle of resized and rotated images, respectively. Examples of the output of our method are shown and comparative results are presented to evaluate the performance of the two-dimensional extension.

%B IEEE International Conference on Image Processing (ICIP) %I IEEE %C Hong Kong, China %P 1745-1748 %8 09/2010 %G eng %R 10.1109/ICIP.2010.5652513 %0 Conference Paper %B IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) %D 2010 %T Wideband Spectral Estimation from Compressed Measurements Exploiting Spectral a priori Information in Cognitive Radio Systems %A Gonzalo Vázquez-Vilar %A R. López-Valcarce %A C. Mosquera %A Nuria González-Prelcic %K cognitive radio %K compressive sampling %K Spectral estimation %B IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) %C Dallas, U.S.A. %8 March 14-19 %G eng %0 Conference Paper %B IEEE International Workshop on Information Forensics and Security (WIFS) %D 2009 %T Blind decoder for binary probabilistic traitor tracing codes %A Luis Pérez-Freire %A Teddy Furon %K collusion %K information theory %K Tardos %K Traitor tracing %K watermarking %B IEEE International Workshop on Information Forensics and Security (WIFS) %C London, UK %P 56-60 %8 6-9 December %G eng %0 Journal Article %J IEEE Transactions on Communications %D 2009 %T Cramer-Rao Lower Bound and EM Algorithm for Envelope-Based SNR Estimation of Nonconstant Modulus Constellations %A Wilfried Gappmair %A R. López-Valcarce %A C. Mosquera %B IEEE Transactions on Communications %V 57 %P 1622 - 1627 %8 june %G eng %0 Conference Paper %B Asilomar Conference on Signals, Systems and Computers %D 2009 %T A Dynamic Spectrum Leasing (DSL) Framework for Spectrum Sharing in Cognitive Radio Networks %A Sudhaman K. Jayaweera %A C. Mosquera %B Asilomar Conference on Signals, Systems and Computers %G eng %0 Conference Paper %B ACM Workshop on Multimedia and Security (MMSEC) %D 2009 %T EM decoding of Tardos traitor tracing codes %A Teddy Furon %A Luis Pérez-Freire %K collusion channel %K Expectation-Maximization %K iterative decoding %K Tardos code %K Traitor tracing %K watermarking %B ACM Workshop on Multimedia and Security (MMSEC) %C Princeton, NJ, USA %8 7-8 September %G eng %0 Conference Paper %B International Workshop on Information Hiding (IH) %D 2009 %T Estimating the minimal length of Tardos code %A Teddy Furon %A Luis Pérez-Freire %A Arnaud Guyader %A Frédéric Cérou %K Fingerprinting %K Rare event %K Tardos code %K Traitor tracing %K watermarking %B International Workshop on Information Hiding (IH) %S Lecture Notes in Computer Science %C Darmstadt, Germany %8 7-10 June %G eng %0 Conference Paper %B IEEE International Workshop on Information Forensics and Security (WIFS) %D 2009 %T AN EXTENDED ANALYSIS OF DISCRETE FOURIER TRANFORM - RATIONAL DITHER MODULATION FOR NON-WHITE HOSTS %A Scagliola, Michele %A Fernando Pérez-González %A Guccione, Pietro %K data hiding %K dither modulation %K filtering %K non-white Gaussian hosts %K watermarking %B IEEE International Workshop on Information Forensics and Security (WIFS) %I IEEE %C London, U.K. %8 December %G eng %0 Journal Article %J EURASIP Journal on Information Security %D 2009 %T High-rate data-hiding robust to linear filtering for colored hosts %A Scagliola, Michele %A Fernando Pérez-González %A Guccione, Pietro %K data-hiding %K rational dither modulation %K watermarking %B EURASIP Journal on Information Security %G eng %0 Conference Paper %B Media Forensics and Security %D 2009 %T Model-based steganalysis using invariant features %A Tu-Thach Quach %A Fernando Pérez-González %A Gregory L. Heileman %K Invariant features %K Model-based %K Steganalysis %B Media Forensics and Security %C San Jose, CA, U.S.A. %8 January %G eng %0 Conference Paper %B IEEE International Conference on Image Processing (ICIP) %D 2009 %T Modeling Magnitudes of Gabor Coefficients: The β-Rayleigh Distribution %A Daniel González-Jiménez %A Enrique Argones-Rúa %A Fernando Pérez-González %A José Luis Alba-Castro %K Gabor %K generalized Gaussian %K Rayleigh %K watermarking %B IEEE International Conference on Image Processing (ICIP) %I IEEE %C Cairo, Egypt %8 November %G eng %0 Conference Paper %B International Conference on Cognitive Radio Oriented Wireless Networks and Communications (Crowncom) %D 2009 %T Multiantenna detection of multicarrier primary signals exploiting spectral a priori information %A R. López-Valcarce %A Gonzalo Vázquez-Vilar %A Marcos Álvarez-Díaz %B International Conference on Cognitive Radio Oriented Wireless Networks and Communications (Crowncom) %C Hannover, Germany %8 June 22-24 %G eng %0 Conference Paper %B IEEE International Conference on Image Processing (ICIP) %D 2009 %T Performance Analysis of Fridrich-Goljan Self-Embedding Authentication Method %A Gabriel Domínguez-Conde %A Pedro Comesaña %A Fernando Pérez-González %K cryptography %K error statistics %K false negative probabilities %K false positive probabilities %K Fridrich-Goljan self-embedding authentication method %K hash bit errors %K image authentication method %K image coding %K message authentication %K performance analysis %K robust hashing %K watermarking %B IEEE International Conference on Image Processing (ICIP) %C Cairo, Egypt %8 November %G eng %0 Journal Article %J IEEE Transactions on Information Forensics and Security %D 2009 %T Performance Analysis of Fridrich-Goljan Self-Embedding Authentication Method %A Gabriel Domínguez-Conde %A Pedro Comesaña %A Fernando Pérez-González %K cryptography %K error statistics %K false negative probabilities %K false positive probabilities %K Fridrich-Goljan self-embedding authentication method %K hash bit errors %K image authentication method %K image coding %K message authentication %K performance analysis %K robust hashing %K watermarking %B IEEE Transactions on Information Forensics and Security %V 4 %P 570-577 %8 Sept. %G eng %0 Conference Paper %B Signal Processing in the Encrypted Domain (SPEED) Workshop %D 2009 %T Secure Direct and Iterative Protocols for Solving Systems of Linear Equations %A Juan Ramón Troncoso-Pastoriza %A Pedro Comesaña %A Fernando Pérez-González %K iterative protocol %K privacy %K security %K systems of linear equations %K watermarking %B Signal Processing in the Encrypted Domain (SPEED) Workshop %C Lausanne, Switzerland %P 122–141 %8 September %G eng %0 Conference Paper %B IEEE International Conference on Image Processing (ICIP) %D 2009 %T Skewed Log-Stable model for natural images pixel block-variance %A Juan Ramón Troncoso-Pastoriza %A Fernando Pérez-González %K Doubly stochastic model %K Image block-variance %K Log-stable distribution %K Lognormal distribution %K watermarking %B IEEE International Conference on Image Processing (ICIP) %I IEEE %C Cairo, Egypt %8 November %G eng %0 Journal Article %J IEEE Transactions on Information Forensics and Security %D 2009 %T Spread spectrum watermarking security %A Luis Pérez-Freire %A Fernando Pérez-González %K data-hiding %K security %K watermarking %B IEEE Transactions on Information Forensics and Security %V 4 %P 2-24 %8 March %G eng %0 Conference Paper %B IEEE Broadband Wireless Access Workshop %D 2009 %T A Unified Framework for Dynamic Spectrum Leasing (DSL) in Cognitive Radios %A Sudhaman K. Jayaweera %A Kamrul Hakim %A C. Mosquera %B IEEE Broadband Wireless Access Workshop %G eng %0 Conference Paper %B ACM Workshop on Digital Rights Management (DRM) %D 2009 %T Videosurveillance and privacy: covering the two sides of the mirror with DRM %A Juan Ramón Troncoso-Pastoriza %A Pedro Comesaña %A Luis Pérez-Freire %A Fernando Pérez-González %K access control %K privacy %K rights management %K security %K videosurveillance %K watermarking %B ACM Workshop on Digital Rights Management (DRM) %I ACM %C Chicago, IL, USA %8 November %G eng %0 Conference Paper %B IEEE Workshop on Signal Processing Advances in Wireless Communications (SPAWC) %D 2009 %T Wideband Spectrum Sensing in Cognitive Radio: Joint Estimation of Noise Variance and Multiple Signal Levels %A R. López-Valcarce %A Gonzalo Vázquez-Vilar %B IEEE Workshop on Signal Processing Advances in Wireless Communications (SPAWC) %C Perugia, Italy %8 June 21-24 %G eng %0 Conference Paper %B IEEE International Workshop on Information Forensics and Security (WIFS) %D 2009 %T Worst case attacks against binary probabilistic traitor tracing codes %A Teddy Furon %A Luis Pérez-Freire %K collusion %K information theory %K Tardos %K Traitor tracing %K watermarking %B IEEE International Workshop on Information Forensics and Security (WIFS) %C London, UK %P 46-50 %8 6-9 December %G eng %0 Conference Paper %B Security, Steganography, and Watermarking of Multimedia Contents %D 2008 %T Asymptotically optimum embedding strategy for one-bit watermarking under Gaussian attacks %A Pedro Comesaña %A Neri Merhav %A Mauro Barni %E Edward J. Delp %E Ping W. Wong %E Jana Dittmann %E Nasir D. Memon %B Security, Steganography, and Watermarking of Multimedia Contents %S Proc. of SPIE %I SPIE %C San Jose, CA, USA %V 6819 %8 January %G eng %0 Thesis %D 2008 %T Digital Watermarking Security %A Luis Pérez-Freire %K data-hiding %K security %K watermarking %I University of Vigo, Spain %G eng %9 phd %0 Conference Paper %B International Workshop on Information Hiding (IH) %D 2008 %T Distortion Optimization of Model-Based Secure Embedding Schemes for Data-Hiding %A Benjamin Mathon %A Patrick Bas %A François Cayre %A Fernando Pérez-González %K data hiding %K Distortion Optimization %K Secure Embedding %B International Workshop on Information Hiding (IH) %C Santa Barbara, CA, U.S.A. %8 May %G eng %0 Conference Paper %B Sensor, Signal and Information Processing (SenSIP) Workshop %D 2008 %T Distributed Estimation: Do Not Trust Gossips %A C. Mosquera %A Sudhaman K. Jayaweera %K distributed estimation %K sensor network %B Sensor, Signal and Information Processing (SenSIP) Workshop %C Sedona (Arizona) %G eng %0 Conference Paper %B IEEE International Workshop on Signal Processing Advances in Wireless Communications %D 2008 %T Distributed Estimation with Noisy Exchanges %A C. Mosquera %A R. López-Valcarce %A Sudhaman K. Jayaweera %K distributed estimation %K sensor network %B IEEE International Workshop on Signal Processing Advances in Wireless Communications %C Recife, Brazil %G eng %0 Journal Article %J IEEE Signal Processing Letters %D 2008 %T Distributed Sequential Estimation with Noisy, Correlated Observations %A Sudhaman K. Jayaweera %A C. Mosquera %B IEEE Signal Processing Letters %V 15 %G eng %0 Conference Paper %B IEEE Sensor Array and Multichannel Signal Processing Workshop %D 2008 %T Entangled Kalman Filters for Cooperative Estimation %A C. Mosquera %A Sudhaman K. Jayaweera %K distributed estimation %K sensor network %B IEEE Sensor Array and Multichannel Signal Processing Workshop %C Darmstadt (Germany) %G eng %0 Conference Paper %B European Signal Processing Conference (EUSIPCO) %D 2008 %T A family of frequency estimators using higher-order sample covariance lags for real sinusoid detection %A R. Elasmi-Ksibi %A R. López-Valcarce %A H. Besbes %A S. Cherif %A M. Jaidane %K Frequency estimator %K Sinusoid detection %B European Signal Processing Conference (EUSIPCO) %C Lausanne, Switzerland %8 August %G eng %0 Conference Paper %B European Signal Processing Conference (EUSIPCO) %D 2008 %T Lattice implementation of Sum-squared Auto-correlation Minimization (SAM) channel shortener %A E. Ben Salem %A R. López-Valcarce %A S. Cherif %A H. Besbes %K Blind Adaptation %K Lattice %K SAM %B European Signal Processing Conference (EUSIPCO) %C Lausanne, Switzerland %8 August %G eng %0 Conference Paper %B IEEE International Workshop on Signal Processing Advances in Wireless Communications %D 2008 %T Maximum Likelihood SNR Estimation for Asynchronously Oversampled OFDM Signals %A R. López-Valcarce %A C. Mosquera %K estimation %K ML %K OFDM %K SNR %B IEEE International Workshop on Signal Processing Advances in Wireless Communications %C Recife, Brazil %G eng %0 Conference Paper %B International Symposium on Communication Systems, Networks and Signal Processing (CNSDSP) %D 2008 %T ML and EM Algorithm for non-data-aided SNR Estimation of Linearly Modulated Signals %A Wilfried Gappmair %A R. López-Valcarce %A C. Mosquera %K EM %K ML %K SNR estimation %B International Symposium on Communication Systems, Networks and Signal Processing (CNSDSP) %P 530-534 %G eng %0 Journal Article %J IEEE Transactions on Signal Processing %D 2008 %T Non-Data-Aided Symbol Rate Estimation of Linearly Modulated Signals %A C. Mosquera %A Sandro Scalise %A R. López-Valcarce %B IEEE Transactions on Signal Processing %8 February %G eng %0 Journal Article %J IEEE Transactions on Information Forensics and Security %D 2008 %T Quantization-Based Data-Hiding Robust to Linear Time-Invariant Filtering %A Fernando Pérez-González %A C. Mosquera %K data-hiding %K watermarking %B IEEE Transactions on Information Forensics and Security %V 3 %P 137-152 %8 June %G eng %0 Journal Article %J Transactions on Data Hiding and Multimedia Security III %D 2008 %T Quantization-Based Methods: Additive Attacks Performance Analysis %A Jose Emilio Vila-Forcén %A Sviatoslav Voloshynovskiy %A Oleksiy Koval %A Fernando Pérez-González %A Thierry Pun %K data-hiding %K watermarking %B Transactions on Data Hiding and Multimedia Security III %V 4920 %P 70-90 %G eng %0 Journal Article %J IEEE Transactions on Information Forensics and Security %D 2008 %T Security of lattice-based data hiding against the Watermarked Only Attack %A Luis Pérez-Freire %A Fernando Pérez-González %K data-hiding %K security %K watermarking %B IEEE Transactions on Information Forensics and Security %V 3 %P 593-610 %8 December %G eng %0 Conference Paper %B Advanced Satellite Mobile Systems Conference %D 2008 %T SNR Estimation with Heterogeneous Frames %A Marcos Álvarez-Díaz %A R. López-Valcarce %A C. Mosquera %B Advanced Satellite Mobile Systems Conference %C Bologna, Italy %8 August 26-28 %G eng %0 Conference Paper %B IEEE International Conference on Image Processing (ICIP) %D 2007 %T Benford's Law in Image Processing %A Fernando Pérez-González %A Gregory L. Heileman %A Chaouki T. Abdallah %K benford %K benford's-law %B IEEE International Conference on Image Processing (ICIP) %C San Antonio, TX, USA %8 September %G eng %0 Journal Article %J EURASIP Journal on Information Security %D 2007 %T Breaking the BOWS Watermarking System: Key Guessing and Sensitivity Attacks %A Pedro Comesaña %A Fernando Pérez-González %K data-hiding %K oracle %K sensitivity %K watermarking %B EURASIP Journal on Information Security %V 2007 %8 February %G eng %0 Conference Paper %B ACM Workshop on Multimedia and Security (MMSEC) %D 2007 %T On the capacity of stegosystems %A Pedro Comesaña %A Fernando Pérez-González %K data-hiding %K steganography %K watermarking %B ACM Workshop on Multimedia and Security (MMSEC) %C Dallas, TX, USA %P 1261-1264 %8 September %G eng %0 Book %D 2007 %T Comunicaciones Digitales %A Antonio Artés-Rodríguez %A Fernando Pérez-González %A Jesús Cid-Sueiro %A R. López-Valcarce %A C. Mosquera %A Fernando Pérez-Cruz %I Pearson - Prentice Hall %8 May %G eng %0 Book Section %D 2007 %T Digital Satellite Communications %A C. Mosquera %A M. L. Boucheret %A M. Bousquet %A S. Cioni %A Wilfried Gappmair %A R. Pedone %A Sandro Scalise %A P. Skoutaridis %A M. Villanti %I Springer %G eng %& Parameter Estimation and Synchronization %0 Book Section %D 2007 %T Digital Satellite Communications %A Sandro Scalise %A L. Castanet %A M. Luglio %A Neri, Massimo %A Marcos Álvarez-Díaz %A J. Bito %A M. Bousquet %A I. Frigyes %A P. Horvath %A Axel Jahn %A M. Krejcarek %A J. Lemorton %A S. Morosi %A M. A. Vázquez-Castro %I Springer %C New York %P - %8 April %G eng %& Satellite Channel Impairments %0 Book Section %D 2007 %T Digital Satellite Communications %A R. Pedone %A G. Albertazzi %A P.T. Mathiopoulos %A C. Mosquera %A N. Sagias %A M. Villanti %I Springer %G eng %& Theoretical Background %0 Book Section %D 2007 %T Digital Satellite Communications %A A. A. Rontogiannis %A Marcos Álvarez-Díaz %A M. Casadei %A V. Dalakas %A A. Duverdier %A F. J. González-Serrano %A M. Iubatti %A T. Javornik %A L. Lapierre %A Neri, Massimo %A P. Salmi %I Springer %C New York %P - %8 April %G eng %& Distortion Countermeasures %0 Conference Paper %B Third Wavila Challenge (WaCha) %D 2007 %T Disclosing secrets in watermarking and data hiding %A Luis Pérez-Freire %A Fernando Pérez-González %K data-hiding %K security %K watermarking %B Third Wavila Challenge (WaCha) %S ECRYPT proceedings series from the Otto-von-Guericke University, Magdeburg, Germany %C Saint-Malo, France %8 14 June %G eng %0 Conference Paper %B Security, Steganography, and Watermarking of Multimedia Contents %D 2007 %T On Distortion Measures Associated to Random Desynchronization Attacks %A Félix Balado %A Fernando Pérez-González %E Edward J. Delp %E Ping W. Wong %K data-hiding %K desynchronization %K watermarking %B Security, Steganography, and Watermarking of Multimedia Contents %S Proc. of SPIE %I SPIE %C San Jose, California, USA %8 January %G eng %0 Conference Paper %B International Workshop on Digital Watermarking (IWDW) %D 2007 %T Dither modulation in the logarithmic domain %A Pedro Comesaña %A Fernando Pérez-González %K data-hiding %K watermarking %B International Workshop on Digital Watermarking (IWDW) %C Guangzhou, China %P 1261-1264 %8 December %G eng %0 Conference Paper %B Security, Steganography, and Watermarking of Multimedia Contents %D 2007 %T Efficient Non-Interactive Zero-Knowledge Watermark Detector Robust to Sensitivity Attacks %A Juan Ramón Troncoso-Pastoriza %A Fernando Pérez-González %E Edward J. Delp %E Ping W. Wong %K data-hiding %K sensitivity %K watermarking %K zero-knowledge %B Security, Steganography, and Watermarking of Multimedia Contents %S Proc. of SPIE %I SPIE %C San Jose, California, USA %8 January %G eng %0 Journal Article %J EURASIP Journal on Information Security %D 2007 %T Efficient Zero-Knowledge Watermark Detection with Improved Robustness to Sensitivity Attacks %A Juan Ramón Troncoso-Pastoriza %A Fernando Pérez-González %K data-hiding %K sensitivity %K watermarking %K zero-knowledge %B EURASIP Journal on Information Security %G eng %0 Conference Paper %B International Workshop on Information Hiding (IH) %D 2007 %T Exploiting security holes in lattice data hiding %A Luis Pérez-Freire %A Fernando Pérez-González %K data-hiding %K security %K watermarking %B International Workshop on Information Hiding (IH) %S Lecture Notes in Computer Science %I Springer-Verlag Heidelberg %C Saint-Malo, France %8 11-13 June %G eng %0 Conference Paper %B Signal Processing Advances in Wireless Communications, 2007. SPAWC 2007. IEEE 8th Workshop on %D 2007 %T Fast-fading channel estimator using DCT and simplified kalman filter %A Schmidt, J.F. %A Cousseau, J.E. %A Wichman, R. %A Gregorio, F.H. %K band-pass filters %K basis function approximations %K channel coefficient %K channel Doppler spectrum %K channel estimation %K channel estimator %K channel variations %K decoupled parameters %K discrete cosine transform %K discrete cosine transforms %K Doppler effect %K fading channels %K fast-fading channel %K Kalman filter %K Kalman filters %K low complexity estimator %K narrow-band filters %K passband filters %K training symbols %B Signal Processing Advances in Wireless Communications, 2007. SPAWC 2007. IEEE 8th Workshop on %P 1 -5 %8 june %G eng %R 10.1109/SPAWC.2007.4401355 %0 Conference Paper %B European Control Conference (ECC) %D 2007 %T A Generalization of Benford's Law and Its Application to Images %A Fernando Pérez-González %A Gregory L. Heileman %A Chaouki T. Abdallah %K benford %K benford's-law %B European Control Conference (ECC) %C Kos, Greece %8 July %G eng %0 Conference Paper %B IEEE Workshop on Signal Processing Advances in Wireless Communications (SPAWC) %D 2007 %T Iterative Envelope-Based SNR Estimation for Non-Constant Modulus Constellations %A R. López-Valcarce %A C. Mosquera %A Wilfried Gappmair %K EM %K SNR %K synchronization %B IEEE Workshop on Signal Processing Advances in Wireless Communications (SPAWC) %G eng %0 Conference Paper %B IEEE International Conference on Image Processing (ICIP) %D 2007 %T Modeling Gabor coefficients via Generalized Gaussian Distributions for face recognition %A Daniel González-Jiménez %A Fernando Pérez-González %A Pedro Comesaña %A Luis Pérez-Freire %A José Luis Alba-Castro %K biometrics %K face-recognition %B IEEE International Conference on Image Processing (ICIP) %C San Antonio, TX, USA %P 1261-1264 %8 September %G eng %0 Conference Paper %B International Workshop on Satellite and Space Communications (IWSSC) %D 2007 %T Non-Linear Interference Mitigation for Broadband Multimedia Satellite Systems %A Marcos Álvarez-Díaz %A Nicolas Courville %A C. Mosquera %A Gianluigi Liva %A Giovanni Emanuele Corazza %B International Workshop on Satellite and Space Communications (IWSSC) %C Salzburg, Austria %8 September 13-14 %G eng %0 Conference Paper %B Security, Steganography, and Watermarking of Multimedia Contents %D 2007 %T A Novel Interpretation of Content Authentication %A Pedro Comesaña %A Félix Balado %A Fernando Pérez-González %E Edward J. Delp %E Ping W. Wong %K authentication %K data-hiding %K watermarking %B Security, Steganography, and Watermarking of Multimedia Contents %S Proc. of SPIE %I SPIE %C San Jose, California, USA %8 January %G eng %0 Generic %D 2007 %T Practical estimators of the secret spreading vector for Improved Spread Spectrum modulations. Statistical analysis and results %A Luis Pérez-Freire %K data-hiding %K security %K watermarking %I Signal Theory and Communications Department, University of Vigo, Spain %8 November %G eng %9 Internal report %0 Conference Paper %B ACM Conference on Computer and Communications Security (CCS) %D 2007 %T Privacy Preserving Error Resilient DNA Searching through Oblivious Automata %A Juan Ramón Troncoso-Pastoriza %A Stefan Katzenbeisser %A Mehmet Celik %K DNA %K privacy %K security %K watermarking %B ACM Conference on Computer and Communications Security (CCS) %I ACM Press %C Alexandria, Virginia, USA %P 519–528 %8 Oct 29–Nov 2 %G eng %0 Conference Paper %B IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) %D 2007 %T Putting Reproducible Signal Processing into Practice: A Case Study in Watermarking %A Mauro Barni %A Fernando Pérez-González %A Pedro Comesaña %A Guido Bartoli %K data-hiding %K watermarking %B IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) %C Honolulu, HW, USA %V 4 %P 1261-1264 %8 April %G eng %0 Conference Paper %B International Workshop on Satellite and Space Communications (IWSSC) %D 2007 %T Satellite Communications: Research Trends and Open Issues %A Alessandro Vanelli-Coralli %A Giovanni Emanuele Corazza %A G.K. Karagiannidis %A P.T. Mathiopoulos %A D.S. Michalopoulos %A C. Mosquera %A S. Papaharalabos %A Sandro Scalise %K satellite communications %B International Workshop on Satellite and Space Communications (IWSSC) %G eng %0 Conference Paper %B ACM Workshop on Multimedia and Security (MMSEC) %D 2007 %T A Secure Multidimensional Point Inclusion Protocol %A Juan Ramón Troncoso-Pastoriza %A Stefan Katzenbeisser %A Mehmet Celik %A Aweke Lemma %K multiparty computation %K privacy %K security %K watermarking %B ACM Workshop on Multimedia and Security (MMSEC) %C Dallas, Texas, USA %P 109–120 %8 September %G eng %0 Conference Paper %B Security, Steganography, and Watermarking of Multimedia Contents %D 2007 %T Security of Spread-Spectrum-Based Data Hiding %A Luis Pérez-Freire %A Pierre Moulin %A Fernando Pérez-González %E Edward J. Delp %E Ping W. Wong %K data-hiding %K security %K watermarking %B Security, Steganography, and Watermarking of Multimedia Contents %S Proc. of SPIE %I SPIE %C San Jose, California, USA %8 January %G eng %0 Journal Article %J IEEE Communications Letters %D 2007 %T Sixth-Order Statistics-Based Non-Data-Aided SNR Estimation %A R. López-Valcarce %A C. Mosquera %B IEEE Communications Letters %V 11 %P 351-353 %8 April %G eng %0 Conference Paper %B IEEE International Conference on Image Processing (ICIP) %D 2007 %T Statistical Analysis of a Linear Algebra Asymmetric Watermarking Scheme %A G. Boato %A C. Fontanari %A F. G. B. De Natale %A Fernando Pérez-González %K watermarking %B IEEE International Conference on Image Processing (ICIP) %C San Antonio, TX, USA %P 1261-1264 %8 September %G eng %0 Conference Paper %B Security, Steganography, and Watermarking of Multimedia Contents %D 2007 %T Two different approaches for attacking BOWS %A Pedro Comesaña %A Fernando Pérez-González %E Edward J. Delp %E Ping W. Wong %K BOWS %K data-hiding %K sensitivity %K watermarking %B Security, Steganography, and Watermarking of Multimedia Contents %S Proc. of SPIE %I SPIE %C San Jose, California, USA %8 January %G eng %0 Conference Paper %B IEEE International Conference on Image Processing (ICIP) %D 2007 %T On a watermarking scheme in the logarithmic domain and its perceptual advantages %A Pedro Comesaña %A Fernando Pérez-González %K data-hiding %K watermarking %B IEEE International Conference on Image Processing (ICIP) %C San Antonio, TX, USA %P 1261-1264 %8 September %G eng %0 Journal Article %J IEEE Transactions on Information Forensics and Security %D 2006 %T An accurate analysis of scalar quantization-based data-hiding %A Luis Pérez-Freire %A Fernando Pérez-González %A Sviatoslav Voloshynovskiy %K data-hiding %K security %K watermarking %B IEEE Transactions on Information Forensics and Security %V 1 %P 80-86 %8 March %G eng %0 Conference Paper %B ACM Workshop on Multimedia and Security (MMSEC) %D 2006 %T On achievable security levels for lattice data hiding in the Known Message Attack scenario %A Luis Pérez-Freire %A Fernando Pérez-González %A Teddy Furon %K data-hiding %K security %K watermarking %B ACM Workshop on Multimedia and Security (MMSEC) %I ACM %C Geneva, Switzerland %P 68-79 %8 September %G eng %0 Conference Paper %B International Symposium on Image/Video Communications (ISIVC) %D 2006 %T Analysis of non-data-aided magnitude gain estimators %A R. López-Valcarce %K Digital Communications %K gain estimation %K synchronization %B International Symposium on Image/Video Communications (ISIVC) %C Hammamet, Tunisia %G eng %0 Conference Paper %B IEEE Workshop on Signal Processing Advances in Wireless Communications (SPAWC) %D 2006 %T Blind carrier phase estimation for non-equiprobable constellations %A R. López-Valcarce %A C. Mosquera %K Digital Communications %K phase estimation %K signal shaping %K synchronization %K Tomlinson-Harashima precoding %B IEEE Workshop on Signal Processing Advances in Wireless Communications (SPAWC) %C Cannes, France %G eng %0 Journal Article %J IEE Proceedings on Information Security %D 2006 %T Blind Newton Sensitivity Attack %A Pedro Comesaña %A Luis Pérez-Freire %A Fernando Pérez-González %K data-hiding %K watermarking %B IEE Proceedings on Information Security %V 153 %P 115-125 %8 September %G eng %0 Conference Paper %B Security, Steganography, and Watermarking of Multimedia Contents %D 2006 %T The blind Newton senstivity attack %A Pedro Comesaña %A Luis Pérez-Freire %A Fernando Pérez-González %E Edward J. Delp %E Ping W. Wong %K data-hiding %K watermarking %B Security, Steganography, and Watermarking of Multimedia Contents %S Proc. of SPIE %I SPIE %C San Jose, California, USA %V 5306 %P 592-601 %8 January %G eng %0 Journal Article %J IEEE Transactions on Signal Processing %D 2006 %T On distortion-compensated Dither Modulation data-hiding with repetition coding %A Pedro Comesaña %A Fernando Pérez-González %A Félix Balado %K data-hiding %K watermarking %B IEEE Transactions on Signal Processing %V 54 %P 585-600 %8 February %G eng %0 Conference Paper %B Security, Steganography, and Watermarking of Multimedia Contents %D 2006 %T High-rate quantization data hiding robust to arbitrary linear filtering attacks %A Fernando Pérez-González %A C. Mosquera %A Marcos Álvarez-Díaz %A Reginald Lagendijk %E Edward J. Delp %E Ping W. Wong %K data-hiding %K watermarking %B Security, Steganography, and Watermarking of Multimedia Contents %S Proc. of SPIE %I SPIE %C San Jose, California, USA %V 5306 %P 592-601 %8 January %G eng %0 Journal Article %J IEEE Signal Processing Letters %D 2006 %T The impact of the cropping attack on scalar STDM data hiding %A Pedro Comesaña %A Fernando Pérez-González %K data-hiding %K watermarking %B IEEE Signal Processing Letters %V 13 %P 353-356 %8 June %G eng %0 Journal Article %J IEE Proceedings on Information Security %D 2006 %T Improving the performance of RDM watermarking by means of trellis coded quantisation %A Andrea Abrardo %A Mauro Barni %A Fernando Pérez-González %A C. Mosquera %K data-hiding %K watermarking %B IEE Proceedings on Information Security %V 153 %P 107-114 %8 September %G eng %0 Conference Paper %B International Workshop on Multimedia Content Representation, Classification and Security %D 2006 %T A novel model for the print-and-capture channel in 2D bar codes %A Alberto Malvido %A Fernando Pérez-González %A Armando Cousiño %E Bilge Gunsel %E Anil K. Jain %E A. Murat Tekalp %E Bülent Sankur %K bar-codes %K visible-encryption %B International Workshop on Multimedia Content Representation, Classification and Security %S Lecture Notes in Computer Science %I Springer-Verlag Heidelberg %C Istambul, Turkey %V 4105 %P 627-634 %8 September %G eng %0 Journal Article %J Signal Processing %D 2006 %T Robustness Improvement of Known-Host-State Watermarking Using Host Statistics %A Oleksiy Koval %A Sviatoslav Voloshynovskiy %A Jose Emilio Vila-Forcén %A Fernando Pérez-González %A Frederic Deguillaume %A Thierry Pun %K data-hiding %K watermarking %B Signal Processing %V 86 %P 1076-1088 %8 May %G eng %0 Journal Article %J International Journal of Adaptive Control and Signal Processing %D 2006 %T Second-order blind algorithms for adaptive recursive linear equalizers: Analysis and lattice implementation %A R. López-Valcarce %K adaptive IIR filters %K blind equalization %K Digital Communications %K lattice filters %B International Journal of Adaptive Control and Signal Processing %V 20 %P 265–289 %8 August %G eng %0 Conference Paper %B Security, Steganography, and Watermarking of Multimedia Contents %D 2006 %T Secret dither estimation in lattice-quantization data hiding: a set-membership approach %A Luis Pérez-Freire %A Fernando Pérez-González %A Pedro Comesaña %E Edward J. Delp %E Ping W. Wong %K data-hiding %K security %K watermarking %B Security, Steganography, and Watermarking of Multimedia Contents %S Proc. of SPIE %I SPIE %C San Jose, California, USA %V 5306 %P 592-601 %8 January %G eng %0 Journal Article %J IEEE Transactions on Information Forensics and Security %D 2006 %T Security of lattice-based data hiding against the Known Message Attack %A Luis Pérez-Freire %A Fernando Pérez-González %A Teddy Furon %A Pedro Comesaña %K data-hiding %K security %K watermarking %B IEEE Transactions on Information Forensics and Security %V 1 %P 421-439 %8 December %G eng %0 Thesis %D 2006 %T Side-informed data hiding: robustness and security analysis %A Pedro Comesaña %K data-hiding %K watermarking %I University of Vigo, Spain %G eng %9 phd %0 Conference Paper %B International Workshop on Signal Processing for Space Communications (SPSC) %D 2006 %T Symbol-Rate Estimation for DVB-S2 Broadcasting %A C. Mosquera %A Sandro Scalise %A R. López-Valcarce %K DVB %K symbol rate %K synchronization %B International Workshop on Signal Processing for Space Communications (SPSC) %G eng %0 Conference Paper %B IEEE Workshop on Signal Processing Advances in Wireless Communications (SPAWC) %D 2006 %T Toward a theory of multirate nonlinear systems %A R. López-Valcarce %A Soura Dasgupta %K multirate systems %K nonlinear filters %K polyphase filters %B IEEE Workshop on Signal Processing Advances in Wireless Communications (SPAWC) %C Cannes, France %G eng %0 Conference Paper %B International Workshop on Satellite and Space Communications (IWSSC) %D 2006 %T Trellis Shaping Techniques for Satellite Telecommunication Systems %A Marcos Álvarez-Díaz %A Neri, Massimo %A C. Mosquera %A Giovanni Emanuele Corazza %K Digital Communications %K precoding %K satellite communications %B International Workshop on Satellite and Space Communications (IWSSC) %C Leganés, Spain %8 September %G eng %0 Journal Article %J Transactions on Data Hiding and Multimedia Security I %D 2006 %T Watermarking security: a survey %A Luis Pérez-Freire %A Pedro Comesaña %A Juan Ramón Troncoso-Pastoriza %A Fernando Pérez-González %K data-hiding %K security %K watermarking %B Transactions on Data Hiding and Multimedia Security I %V 4300 %P 41-72 %8 October %G eng %0 Conference Paper %B ACM Workshop on Multimedia and Security (MMSEC) %D 2006 %T Zero-Knowledge watermark detector robust to sensitivity attacks %A Juan Ramón Troncoso-Pastoriza %A Fernando Pérez-González %K data-hiding %K watermarking %K zero-knowledge %B ACM Workshop on Multimedia and Security (MMSEC) %I ACM %C Geneva, Switzerland %P 97-107 %8 September %G eng %0 Conference Paper %B AIAA International Communications Satellite Systems Conference (ICSSC) %D 2005 %T Aeronautical Channel Model for Broadband L-Band Satellite Communication %A Madhavendra Richharia %A Naveen Kaluvala %A Panos Fines %A Marcos Álvarez-Díaz %A Axel Jahn %K Digital Communications %K L-Band %K satellite communications %B AIAA International Communications Satellite Systems Conference (ICSSC) %C Rome, Italy %8 September 25-28 %G eng %0 Conference Paper %B IEEE Conference on Decision and Control / European Control Conference (CDC/ECC) %D 2005 %T Analysis of a first-order adaptive recursive predictor %A R. López-Valcarce %K adaptive signal processing %K equalization %K second-order statistics %B IEEE Conference on Decision and Control / European Control Conference (CDC/ECC) %C Seville, Spain %G eng %R 10.1109/CDC.2005.1582919 %0 Conference Paper %B Security, Steganography, and Watermarking of Multimedia Contents %D 2005 %T Applying Erez and Ten Brink's Dirty Paper Codes to Data-Hiding %A Pedro Comesaña %A Fernando Pérez-González %A Frans M. J. Willems %E Edward J. Delp %E Ping W. Wong %K data-hiding %K watermarking %B Security, Steganography, and Watermarking of Multimedia Contents %S Proc. of SPIE %I SPIE %C San Jose, California, USA %V 5306 %P 592-601 %8 January %G eng %0 Conference Paper %B Security, Steganography, and Watermarking of Multimedia Contents %D 2005 %T Detection in quantization-based watermarking: performance and security issues %A Luis Pérez-Freire %A Pedro Comesaña %A Fernando Pérez-González %E Edward J. Delp %E Ping W. Wong %K data-hiding %K security %K watermarking %B Security, Steganography, and Watermarking of Multimedia Contents %S Proc. of SPIE %I SPIE %C San Jose, California, USA %V 5306 %P 592-601 %8 January %G eng %0 Conference Paper %B IEEE Workshop on Statistical Signal Processing (SSP) %D 2005 %T Diamond contour-based phase recovery for (cross-)QAM constellations %A Marcos Álvarez-Díaz %A R. López-Valcarce %K adaptive signal processing %K synchronization %B IEEE Workshop on Statistical Signal Processing (SSP) %C Bordeaux, France %G eng %R 10.1109/SSP.2005.1628678 %0 Conference Paper %B Security, Steganography, and Watermarking of Multimedia Contents %D 2005 %T Ensuring Gain Invariance in High-Rate Data-Hiding %A Fernando Pérez-González %A C. Mosquera %A Mauro Barni %A Andrea Abrardo %E Edward J. Delp %E Ping W. Wong %K data-hiding %K watermarking %B Security, Steganography, and Watermarking of Multimedia Contents %S Proc. of SPIE %I SPIE %C San Jose, California, USA %V 5306 %P 592-601 %8 January %G eng %0 Conference Paper %B International Workshop on Information Hiding (IH) %D 2005 %T Fundamentals of data hiding security and their application to spread-spectrum analysis %A Pedro Comesaña %A Luis Pérez-Freire %A Fernando Pérez-González %E Mauro Barni %E Jordi Herrera-Joancomartí %E Stefan Katzenbeisser %E Fernando Pérez-González %K data-hiding %K watermarking %B International Workshop on Information Hiding (IH) %S Lecture Notes in Computer Science %I Springer-Verlag Heidelberg %C Barcelona, Spain %V 3727 %P 131-145 %8 June %G eng %0 Conference Paper %B International Workshop on Information Hiding (IH) %D 2005 %T Information-theoretic analysis of security in side-informed data hiding %A Luis Pérez-Freire %A Pedro Comesaña %A Fernando Pérez-González %E Mauro Barni %E Jordi Herrera-Joancomartí %E Stefan Katzenbeisser %E Fernando Pérez-González %K data-hiding %K security %K watermarking %B International Workshop on Information Hiding (IH) %S Lecture Notes in Computer Science %I Springer-Verlag Heidelberg %V 3727 %P 131-145 %G eng %0 Conference Paper %B International Workshop on Image Analysis for Multimedia Interactive Services (WIAMIS) %D 2005 %T An information-theoretic framework for assessing security in practical watermarking and data hiding scenarios %A Pedro Comesaña %A Luis Pérez-Freire %A Fernando Pérez-González %K data-hiding %K security %K watermarking %B International Workshop on Image Analysis for Multimedia Interactive Services (WIAMIS) %C Montreux, Switzerland %8 April %G eng %0 Conference Paper %B International Workshop on Satellite and Space Communications (IWSSC) %D 2005 %T Joint precoding and predistortion techniques for satellite telecommunication systems %K Digital Communications %K precoding %K satellite communications %B International Workshop on Satellite and Space Communications (IWSSC) %C Siena, Italy %8 September %G eng %0 Journal Article %J IEEE Transactions on Signal Processing %D 2005 %T Rational Dither Modulation: a high-rate data-hiding method robust to gain attacks %A Fernando Pérez-González %A C. Mosquera %A Mauro Barni %A Andrea Abrardo %K data-hiding %K watermarking %B IEEE Transactions on Signal Processing %V 53 %P 3960-3975 %8 October %G eng %0 Journal Article %J IEEE Transactions on Signal Processing %D 2005 %T Realizable minimum mean-squared error channel shorteners %A R. López-Valcarce %K adaptive signal processing %K Channel shortening %B IEEE Transactions on Signal Processing %V 53 %P 4354–4362 %8 November %G eng %R 10.1109/TSP.2005.857050 %0 Conference Paper %B International Workshop on Digital Watermarking (IWDW) %D 2005 %T The return of the sensitivity attack %A Pedro Comesaña %A Luis Pérez-Freire %A Fernando Pérez-González %E Mauro Barni %E Ingemar J. Cox %E Ton Kalker %E H. J. Kim %K data-hiding %K watermarking %B International Workshop on Digital Watermarking (IWDW) %S Lecture Notes in Computer Science %I Springer-Verlag Heidelberg %C Siena, Italy %V 3710 %P 260-274 %8 September %G eng %0 Conference Paper %B Conference on Communications and Multimedia Security (CMS) %D 2005 %T On reversibility of random binning techniques: multimedia perspectives %A Sviatoslav Voloshynovskiy %A Oleksiy Koval %A E. Topak %A Jose Emilio Vila-Forcén %A Pedro Comesaña %A Thierry Pun %K data-hiding %K watermarking %B Conference on Communications and Multimedia Security (CMS) %S Lecture Notes in Computer Science %I Springer-Verlag Heidelberg %C Salzburg, Austria %8 September %G eng %0 Conference Paper %B Security, Steganography, and Watermarking of Multimedia Contents %D 2005 %T Robustness Improvement of Known-Host-State Watermarking Using Host Statistics %A Oleksiy Koval %A Sviatoslav Voloshynovskiy %A Frederic Deguillaume %A Fernando Pérez-González %A Thierry Pun %E Edward J. Delp %E Ping W. Wong %K data-hiding %K watermarking %B Security, Steganography, and Watermarking of Multimedia Contents %S Proc. of SPIE %I SPIE %C San Jose, California, USA %V 5306 %P 592-601 %8 January %G eng %0 Conference Paper %B Security, Steganography, and Watermarking of Multimedia Contents %D 2005 %T Spread-spectrum vs. quantization-based data hiding: misconceptions and implications %A Luis Pérez-Freire %A Fernando Pérez-González %E Edward J. Delp %E Ping W. Wong %K data-hiding %K watermarking %B Security, Steganography, and Watermarking of Multimedia Contents %S Proc. of SPIE %I SPIE %C San Jose, California, USA %V 5306 %P 592-601 %8 January %G eng %0 Conference Paper %B Security, Steganography, and Watermarking of Multimedia Contents %D 2005 %T Worst case additive attack against quantization-based data-hiding methods %A Jose Emilio Vila-Forcén %A Sviatoslav Voloshynovskiy %A Oleksiy Koval %A Fernando Pérez-González %A Thierry Pun %E Edward J. Delp %E Ping W. Wong %K data-hiding %K watermarking %B Security, Steganography, and Watermarking of Multimedia Contents %S Proc. of SPIE %I SPIE %C San Jose, California, USA %V 5306 %P 592-601 %8 January %G eng %0 Conference Paper %B European Signal Processing Conference (EUSIPCO) %D 2004 %T Bias analysis and removal of a microphone array based road traffic speed estimator %A R. López-Valcarce %A D. Hurtado %A C. Mosquera %A Fernando Pérez-González %K microphone arrays %K speed estimation %K traffic monitoring %B European Signal Processing Conference (EUSIPCO) %C Vienna, Austria %G eng %0 Journal Article %J IEEE Transactions on Signal Processing %D 2004 %T Blind input, initial state, and system identification of SIMO Laguerre systems %A Jacob H. Gunther %A R. López-Valcarce %K blind identification %K blind input estimation %K Laguerre systems %K system identification %B IEEE Transactions on Signal Processing %V 52 %P 3357–3369 %8 December %G eng %R 10.1109/TSP.2004.837438 %0 Conference Paper %B Security, Steganography, and Watermarking of Multimedia Contents %D 2004 %T Blind iterative decoding of side-informed data hiding using the Expectation-Maximization algorithm %A Félix Balado %A Fernando Pérez-González %A Pedro Comesaña %E Edward J. Delp %E Ping W. Wong %K data-hiding %K watermarking %B Security, Steganography, and Watermarking of Multimedia Contents %S Proc. of SPIE %I SPIE %C San Jose, California, USA %V 5306 %P 805-815 %8 January %G eng %0 Conference Paper %B International Workshop on Image Analysis for Multimedia Interactive Services (WIAMIS) %D 2004 %T Blind Turbo Decoding of Side-Informed Data Hiding Using Iterative Channel Estimation %A Félix Balado %A Fernando Pérez-González %K data-hiding %K watermarking %B International Workshop on Image Analysis for Multimedia Interactive Services (WIAMIS) %C Lisboa %8 April %G eng %0 Conference Paper %B IEEE Sensor Array and Multichannel Signal Processing Workshop (SAM) %D 2004 %T Broadband analysis of a microphone array based road traffic speed estimator %A R. López-Valcarce %K microphone arrays %K speed estimation %K traffic monitoring %B IEEE Sensor Array and Multichannel Signal Processing Workshop (SAM) %C Sitges, Barcelona, Spain %G eng %R 10.1109/SAM.2004.1503005 %0 Journal Article %J IEE Electronics Letters %D 2004 %T Cost minimisation interpretation of fourth power phase estimator and links to multimodulus algorithm %A R. López-Valcarce %K constant modulus %K Digital Communications %K equalization %K multimodulus %K phase estimation %B IEE Electronics Letters %V 40 %P 278–279 %8 19 February %G eng %0 Journal Article %J EURASIP Journal of Applied Signal Processing %D 2004 %T Estimation of road vehicle speed using two omnidirectional microphones: a maximum likelihood approach %A R. López-Valcarce %A C. Mosquera %A Fernando Pérez-González %K microphone arrays %K speed estimation %K traffic monitoring %B EURASIP Journal of Applied Signal Processing %V 2004 %P 1059–1077 %8 August %G eng %0 Conference Paper %B International Workshop on Image Analysis for Multimedia Interactive Services (WIAMIS) %D 2004 %T Improved Binary Dither-Modulation with perceptual constraints %A Fernando Pérez-González %A Pedro Comesaña %K data-hiding %K watermarking %B International Workshop on Image Analysis for Multimedia Interactive Services (WIAMIS) %C Lisboa, Portugal %8 April %G eng %0 Journal Article %J IEEE Transactions on Signal Processing %D 2004 %T Linear Boundary Extensions for Finite Length Signals and Paraunitary Two-Channel Filter Banks %A M. Elena Domínguez-Jiménez %A Nuria González-Prelcic %B IEEE Transactions on Signal Processing %V 52 %P 3213-3226 %8 November %G eng %0 Journal Article %J IEEE Signal Processing Letters %D 2004 %T Minimum delay spread TEQ design in multicarrier systems %A R. López-Valcarce %K channel shortener %K cyclic prefix %K delay spread %K Digital Communications %K multicarrier communications %K time domain equalizer %B IEEE Signal Processing Letters %V 11 %P 682–685 %8 August %G eng %R 10.1109/LSP.2004.831676 %0 Conference Paper %B Vehicular Technology Conference (VTC) %D 2004 %T Performance of Coding and Synchronization Schemes for a DVB-S Based Air-Interface in the Railway Environment %A Sandro Scalise %A Giorgio Sciascia %A Marcos Álvarez-Díaz %A Harald Ernst %A Rodolfo Mura %K Digital Communications %K DVB-S %K satellite communications %B Vehicular Technology Conference (VTC) %C Milano, Italy %V 1 %P 347-351 %8 May 17-19 %G eng %0 Conference Paper %B International Symposium on Power Line Communications and Its Applications (ISPLC) %D 2004 %T POLI-MAS: Power-Line Multichannel Audio System %A Fernando J. Mato-Méndez %A C. Mosquera %K audio %K multichannel %K PLC %B International Symposium on Power Line Communications and Its Applications (ISPLC) %G eng %0 Conference Paper %B Security, Steganography, and Watermarking of Multimedia Contents %D 2004 %T Quantifying Security Leaks in Spread Spectrum Data Hiding: A Game Theoretic Approach %A Pedro Comesaña %A Fernando Pérez-González %E Edward J. Delp %E Ping W. Wong %K data-hiding %K watermarking %B Security, Steganography, and Watermarking of Multimedia Contents %S Proc. of SPIE %I SPIE %C San Jose, California, USA %V 5306 %P 592-601 %8 January %G eng %0 Conference Paper %B ACM Workshop on Multimedia and Security (MMSEC) %D 2004 %T Quantization-based watermarking performance improvement using host statistics: additive noise attack %A Oleksiy Koval %A Sviatoslav Voloshynovskiy %A Fernando Pérez-González %A Frederic Deguillaume %A Thierry Pun %B ACM Workshop on Multimedia and Security (MMSEC) %C Magdeburg, Germany %8 September 20-21 %G eng %0 Conference Paper %B IEEE International Workshop on Multimedia Signal Processing %D 2004 %T Rational Dither Modulation: a novel data-hiding method robust to value-metric attacks %A Fernando Pérez-González %A Mauro Barni %A Andrea Abrardo %A C. Mosquera %K data-hiding %K watermarking %B IEEE International Workshop on Multimedia Signal Processing %C Siena, Italy %P 139-142 %8 29 Sept - 1 Oct %G eng %0 Journal Article %J IEEE Transactions on Signal Processing %D 2004 %T Realizable linear and decision feedback equalizers: properties and connections %A R. López-Valcarce %K adaptive signal processing %K channel equalization %B IEEE Transactions on Signal Processing %V 52 %P 757–773 %8 March %G eng %1**Best Paper Award** of the IEEE Signal Processing Society (Signal Processing for Communications), 2005