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 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 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 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
%X The 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 Asilomar Conf. on Signals, Systems and Computers
%D 2014
%T Channel estimation in millimeter wave MIMO systems with one-bit quantization
%A Jianhua Mo
%A Phil Schniter
%A Nuria González-Prelcic
%A Robert W. Heath Jr.
%K adaptive signal processing
%K compass
%K mmWave
%B Asilomar Conf. on Signals, Systems and Computers
%G eng
%R 10.1109/ACSSC.2014.7094595
%0 Conference Paper
%B IEEE Global Communications Conference
%D 2014
%T Circular Sparse Rulers Based On Co-prime Sampling For Compressive Power Spectrum Estimation
%A Nuria González-Prelcic
%A M. E. Domíngez-Jiménez
%K cognitive radio
%K compass
%K compressed sensing
%B IEEE Global Communications Conference
%I IEEE
%C Austin, TX
%8 12/2014
%G eng
%R 10.1109/GLOCOM.2014.7037272
%0 Thesis
%D 2014
%T Cognitive and Signal Processing Techniques for Improved Spectrum Exploitation in Wireless Communications
%A Alberto Rico-Alvariño
%K cognitive radio
%K satcom
%I Universidade de Vigo
%C Vigo
%G eng
%0 Conference Paper
%B IEEE Sensor Array Multichannel Signal Process. Workshop (SAM)
%D 2014
%T Cooperative compressive power spectrum estimation
%A Dyonisius D Ariananda
%A Daniel Romero
%A Geert Leus
%K cognitive radio
%K wsn
%B IEEE Sensor Array Multichannel Signal Process. Workshop (SAM)
%G eng
%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 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 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 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 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 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 Conference Paper
%B IST Mobile & Wireless Communications Summit
%D 2003
%T Characterization of the Railroad Satellite Channel within the FIFTH Project
%A Sandro Scalise
%A Marcos Álvarez-Díaz
%A Giorgio Sciascia
%A Rodolfo Mura
%K Digital Communications
%K satellite communications
%B IST Mobile & Wireless Communications Summit
%C Aveiro, Portugal
%8 June 15-18
%G eng
%0 Conference Paper
%B IEEE International Conference on Digital Signal Processing (DSP)
%D 2002
%T Channel equalization with staggered modulation formats
%A R. López-Valcarce
%K Digital Communications
%K equalization
%K staggered modulation
%B IEEE International Conference on Digital Signal Processing (DSP)
%C Santorini, Greece
%P 769–772
%G eng
%0 Conference Paper
%B International Symposium on Power Line Communications and Its Applications (ISPLC)
%D 2001
%T A Channel Model for the Galician Low Voltage Main Network
%A Nuria González-Prelcic
%A C. Mosquera
%A Norberto Degara-Quintela
%A A. Currais
%B International Symposium on Power Line Communications and Its Applications (ISPLC)
%C Malmo, Sweden
%8 April
%G eng
%0 Conference Paper
%B Security and Watermarking of Multimedia Contents
%D 2001
%T Coding at the Sample Level for Data Hiding: Turbo and Concatenated Codes
%A Félix Balado
%A Fernando Pérez-González
%E Ping W. Wong
%E Edward J. Delp
%K data-hiding
%K watermarking
%B Security and Watermarking of Multimedia Contents
%S Proc. of SPIE
%C San José, USA
%V 4314
%P 532–543
%8 January
%G eng
%0 Journal Article
%J Signal Processing
%D 2000
%T Convergence analysis of the multiple-channel filtered-U recursive LMS algorithm for active noise control
%A C. Mosquera
%A Fernando Pérez-González
%K ANC
%K FuRLMS
%K SPR
%B Signal Processing
%V 80
%P 849-856
%G eng
%0 Conference Paper
%B COST #254 Int. Workshop on Intelligent Communications
%D 1998
%T Coding and Synchronization: A Boost and a Bottleneck for the Development of Image Watermarking
%A Juan R. Hernández
%A Fernando Pérez-González
%A José M. Rodríguez
%K data-hiding
%K watermarking
%B COST #254 Int. Workshop on Intelligent Communications
%I SSGRR
%C L'Aquila, Italy
%P 77–82
%8 June
%G eng
%0 Conference Paper
%B IFAC World Congress
%D 1996
%T Characterization and Algebraic Solution to the Extreme-Point Robust SPR Problem
%A Fernando Pérez-González
%A C. Mosquera
%K robust
%K SPR
%B IFAC World Congress
%C San Francisco, CA, USA
%P 391-396
%G eng
%0 Journal Article
%J Signal Processing: Image Communication
%D 1996
%T A comparison of system architectures for intelligent document understanding
%A G. S. D. Farrow
%A C. S. Xydeas
%A J.P. Oakley
%A A. Khorabi
%A Nuria González-Prelcic
%B Signal Processing: Image Communication
%V 9
%P 1-19
%8 November
%G eng
%0 Conference Paper
%B Audio Engineering Society Convention (AES Convention)
%D 1996
%T Considerations on the Performance of Filter Design Methods for Wavelet Packet Audio Decompositions
%A Nuria González-Prelcic
%A S. González-Sánchez
%A Antonio S. Pena
%B Audio Engineering Society Convention (AES Convention)
%C Copenhagen, Denmark
%8 May
%G eng