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 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 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 Conference Paper
%B IEEE Workshop on Information Forensics and Security (WIFS)
%D 2014
%T Detecting Misreporting Attacks to the Proportional Fair Scheduler
%A Schmidt, J.F.
%A R. López-Valcarce
%K adversarial signal processing
%K compass
%X 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 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 %XDistributed 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 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 %XMany 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 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 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 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 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 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 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 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 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 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 Thesis %D 2003 %T Digital image data hiding using side information %A Félix Balado %K data-hiding %K watermarking %I University of Vigo, Spain %G eng %9 phd %0 Conference Paper %B IEEE International Conference on Image Processing (ICIP) %D 2003 %T Dither-Modulation Data hiding with distortion-compensation: exact performance analysis and an improved detector for JPEG attacks. %A Fernando Pérez-González %A Pedro Comesaña %A Félix Balado %K data-hiding %K watermarking %B IEEE International Conference on Image Processing (ICIP) %I IEEE %C Barcelona, Spain %G eng %0 Conference Paper %B Baiona Workshop on Signal Processing in Communications %D 2003 %T DVB-S Air Interface over Railroad Satellite Channel: Performance and Extensions %A Marcos Álvarez-Díaz %A Sandro Scalise %A Giorgio Sciascia %A Rodolfo Mura %A Paolo Conforto %A Harald Ernst %K Digital Communications %K DVB-S %K satellite communications %B Baiona Workshop on Signal Processing in Communications %C Baiona, Spain %8 September 8-10 %G eng %0 Journal Article %J IEEE Transactions on Image Processing %D 2000 %T DCT-Domain Watermarking Techniques for Still Images: Detector Performance Analysis and a New Structure %A Juan R. Hernández %A Martín Amado %A Fernando Pérez-González %K data-hiding %K watermarking %B IEEE Transactions on Image Processing %V 9 %P 55–68 %8 January %G eng %0 Conference Paper %B IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) %D 2000 %T Design of non-expansionist and orthogonal extension methods for tree-structured filter banks %A M. Elena Domínguez-Jiménez %A Nuria González-Prelcic %B IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) %C Estambul, Turkey %8 June %G eng %0 Conference Paper %B Emerging Techniques for Communication Terminals %D 1997 %T Data Hiding for Copyright Protection of Still Images %A Juan R. Hernández %A Fernando Pérez-González %A José M. Rodríguez %K data-hiding %K watermarking %B Emerging Techniques for Communication Terminals %I ENSEEIHT %C Tolouse, France %P 285–289 %8 July %G eng