Walid Hachem, CNRS; Telecom ParisTech

Biography

Walid HACHEM
CNRS / UMR 5141
Telecom ParisTech
COMELEC Department
Room A312

46 rue Barrault
75634 Paris Cedex 13
France.

Phone:	+33 1 45 81 70 54
Fax:	+33 1 45 89 00 20

E-mail:
walid (dot) hachem (at) telecom-paristech (dot) fr

Walid HACHEM

Researcher at the Centre National de la Recherche Scientifique (CNRS).
CNRS LTCI; Telecom ParisTech (*)
COMELEC Department.

(*) The former name of Telecom ParisTech is Ecole Nationale Supérieure des Télécommunications (ENST).

Planches de la journée du GdR ISIS
"Avancées en théorie de l'information",
Télécom ParisTech, le 6 avril 2012

Biography

I was born in Bhamdoun, Lebanon, in 1967. I received the Engineering degree in telecommunications from St Joseph University, Faculté d'ingénierie (ESIB), Beirut, Lebanon, in 1989, the Masters degree from Telecom ParisTech in 1990, the PhD degree in signal processing from Université Paris Est Marne-la-Vallée in 2000 and the "Habilitation à Diriger des Recherches" from Université Paris-Sud (Orsay) in 2006.
Between 1990 and 2000, I worked in the telecommunications industry with Philips T.R.T., then with FERMA, as a signal processing engineer. In 2001, I joined the academia as a faculty member at Supélec. In 2006, I joined the CNRS, where I am now a research director at Telecom ParisTech, COMELEC department.
My teaching and research activities are essentially devoted to signal processing and to communication theory. In particular, I am interested in the performance analysis using large random matrix theory, and in detection and estimation in sensor networks.
I served as an associate editor for the IEEE Transactions on Signal Processing between 2007 and 2010. I am currently "Directeur Scientifique Adjoint" of the research group ("Groupe de Recherche") ISIS.

Publications and Presentations

JOURNAL PAPERS

P. Bianchi, G. Fort and W. Hachem, "Performance of a Distributed Stochastic Approximation Algorithm", submitted, March 2012.
F. Rubio, X. Mestre and W. Hachem, "A CLT on the SNR of diagonally loaded MVDR filters", accepted for publication in IEEE Transactions on Signal Processing in April 2012.
R. Couillet and W. Hachem, "Local failure detection and diagnosis in large sensor networks" , accepted for publication in IEEE Transactions on Information Theory in May 2012.
N. Ksairi, Ph. Ciblat, P. Bianchi, and W. Hachem, "Performance Analysis over Slow Fading Channels of a Half-Duplex Single-Relay Protocol: Decode or Quantize and Forward", accepted for publication in IEEE Transactions on Communications, January 2012 (long version with proofs).
W. Hachem, M. Kharouf, J. Najim and J.W. Silverstein, "A CLT for Information-theoretic statistics of Non-centered Gram random matrices" , accepted in Random Matrices: Theory and Applications, November 2011.
W. Hachem, Ph. Loubaton, X. Mestre, J. Najim and P. Vallet, "Large information plus noise random matrix models and consistent subspace estimation in large sensor networks", accepted for publication in Random Matrices: Theory and Applications.
W. Hachem, Ph. Loubaton, X. Mestre, J. Najim and P. Vallet, "A Subspace Estimator for Fixed Rank Perturbations of Large Random Matrices" , submitted, June 2011.
D. Gregoratti, W. Hachem and X. Mestre, "Randomized Isometric Linear-Dispersion Space-Time Block Coding for the DF Relay Channel", IEEE Transactions on Signal Processing, Vol. 60, No. 1, pages 426-442, January 2012.
W. Hachem, Ph. Loubaton, J. Najim and P. Vallet, "On bilinear forms based on the resolvent of large random matrices" (Extended version), Annales de l'Institut Henri Poincaré, Probabilités et statistiques, accepted.
W. Hachem, E. Moulines and F. Roueff, "Error exponents for Neyman-Pearson detection of a continuous-time Gaussian Markov process from noisy irregular samples", IEEE Transactions on Information Theory, Vol. 57 , No. 6 Page(s) 3899-3914, June 2011.
N. Ksairi, P. Bianchi, Ph. Ciblat and W. Hachem, "Resource Allocation for Downlink Cellular OFDMA Systems, Part I - Optimal Allocation, Part II - Practical Algorithms and Optimal Reuse Factor", IEEE Transactions on Signal Processing Vol 58, No 2, February 2010.
M. Nahas, A. Saadani and W. Hachem, "Performance of Asynchronous Two-Relay Two-Hop Wireless Cooperative Networks", IEEE Transactions on Wireless Communications, Vol. 9, No. 3, March 2010.
A. Kammoun, M. Kharouf, W. Hachem and J. Najim, "BER and Outage Probability Approximations for LMMSE Detectors on Correlated MIMO Channels", IEEE Transactions on Information Theory, Vol 55, No 10, pages 4386-4397, October 2009.
A. Kammoun, M. Kharouf, W. Hachem and J. Najim, "A Central Limit Theorem for the SINR at the LMMSE Estimator Output for Large Dimensional Systems", IEEE Transactions on Information Theory Vol 55, No 11, pages 5048-5063, November 2009.
J. Dumont, W. Hachem, S. Lasaulce, Ph. Loubaton and J. Najim, "On the Capacity Achieving Covariance Matrix for Rician MIMO Channels: An Asymptotic Approach", IEEE Transactions on Information Theory, Vol. 56, n° 3, pp. 1048-1069, March 2010.
W. Hachem, P. Bianchi and Ph. Ciblat, "Outage Probability Based Power and Time Optimization for Relay Networks", IEEE Transactions on Signal Processing, Vol 57, No 2, pages 764-782, February 2009.
W. Hachem, Ph. Loubaton and J. Najim, "A CLT for Information Theoretic Statistics of Gram Random Matrices with a Given Variance Profile", Annals of Applied Probability, Vol. 18, Number 6 (2008), 2071-2130.
W. Hachem, O. Khorunzhiy, Ph. Loubaton, J. Najim, and L. Pastur, "A New Approach for Capacity Analysis of Large Dimensional Multi-Antenna Channels", IEEE Transactions on Information Theory, Vol. 54, No. 9, September 2008, 3987-4004.
S. Sezginer, P. Bianchi, and W. Hachem, "Asymptotic Cramér-Rao Bounds and Training Design for MIMO-OFDMA Uplink Transmissions with Frequency Offset", IEEE Transactions on Signal Processing, July 2007.
S. Gault, W. Hachem, Ph. Ciblat, "Performance Analysis of an OFDMA Transmission System in a Multi-Cell Environment", IEEE Transactions on Communications, April 2007.
W. Hachem, Ph. Loubaton, and J. Najim, "Deterministic Equivalents for Certain Functionals of Large Random Matrices", Annals of Applied Probability, 17 (3), 2007.
B. Mouhouche, Ph. Loubaton and W. Hachem, "Asymptotic Analysis of Reduced-Rank Chip-Level MMSE Equalizers in the Downlink of CDMA Systems", IEEE Transactions on Signal Processing, 55 (6), pages 3048-3060, June 2007.
W. Hachem, Ph. Loubaton, and J. Najim, The Empirical Eigenvalue Distribution of a Gram Matrix: From Independence to Stationarity", Markov Processes and Related Fields 11 (4), 2005.
W. Hachem, Ph. Loubaton, and J. Najim, "The Empirical Distribution of the Eigenvalues of a Gram Matrix with a Given Variance Profile", Annales de l'Institut Henri Poincaré, Probabilités et statistiques, 42(6), pp 649-670, 2006.
S. Gault, W. Hachem, and Ph. Ciblat, "Joint Sampling Clock Offset and Channel Estimation for OFDM Signals : CRB and Algorithms", IEEE Transactions on Signal Processing, May 2006.
J. Fiorina and W. Hachem, "On the Asymptotic Distribution of the Correlation Receiver Output for Time-Hopped UWB Signals", IEEE Transactions on Signal Processing, July 2006.
W. Hachem, "Simple Polynomial Detectors for CDMA Downlink Transmissions on Frequency Selective Channels", IEEE Transactions on Information Theory, January 2004.
J.-M. Chaufray, W. Hachem, and Ph. Loubaton, "Asymptotic Analysis of Optimum and Sub-Optimum CDMA Downlink MMSE Receivers", IEEE Transactions on Information Theory, November 2004.
M. Debbah, W. Hachem, Ph. Loubaton and Marc de Courville, "MMSE Analysis of Certain Large Isometric Random Precoded Systems", IEEE Transactions on Information Theory, Vol. 49, No. 5, pages 1293-1311, May 2003.
W. Hachem, F. Desbouvries and Ph. Loubaton, "MIMO Channel Blind Identification in Presence of Spatially Correlated Noise", IEEE Transactions on Signal Processing, Vol. 50, No. 3, pages 651-661, March 2002.
W. Hachem, F. Desbouvries and Ph. Loubaton, "Identification of certain noisy MA models: new results ", System and Control Letters, 39, 2000, pages 237-243.

CONFERENCE PAPERS

R. Couillet and W. Hachem, "Local Failure Localization in Large Sensor Networks", 45th Asilomar Conference on Signals, Systems and Computers 2011, Pacific Grove.
F. Iutzeler, J. Jakubowicz, W. Hachem and Ph. Ciblat, "Distributed Estimation of the Maximum Value Over a Wireless Sensor Network", 45th Asilomar Conference on Signals, Systems and Computers 2011, Pacific Grove.
P. Bianchi, G. Fort, W. Hachem, and J. Jakubowicz, "Sur un algorithme de Robbins-Monro distribué", GRETSI 2011, Bordeaux.
F. Iutzeler, Ph. Ciblat, W. Hachem, et J. Jakubowicz, "Estimation distribuée du maximum dans un réseau de capteurs", GRETSI 2011, Bordeaux.
P. Bianchi, G. Fort, W. Hachem, and J. Jakubowicz, "Performance Analysis of a Distributed Robbins-Monro Algorithm for Sensor Networks", EUSIPCO 2011, Barcelona.
P. Vallet, W. Hachem, P. Loubaton, X. Mestre and J.Najim, "On the Consistency of the G-MUSIC DoA Estimator", SSP 2011, Nice.
P. Vallet, W. Hachem, P. Loubaton, X. Mestre and J.Najim, "An improved MUSIC algorithm based on low rank perturbation of large random matrices", SSP 2011, Nice.
X. Mestre, P. Vallet, P. Loubaton, and W. Hachem, "Asymptotic Analysis of a Consistent Subspace Estimator for Observations of Increasing Dimensions", SSP 2011, Nice.
P. Bianchi, G. Fort, W. Hachem, and J. Jakubowicz, "Convergence of a Distributed Parameter Estimator for Sensor Networks with Local Averaging of the Estimates", ICASSP 2011, Prague.
F. Rubio, X. Mestre and W. Hachem, "A CLT on the SINR of the Diagonally Loaded Capon/MVDR Beamformer, ICASSP 2011, Prague.
A. Kammoun, M. Kharouf, W. Hachem, J. Najim, and A. El Kharroubi, "On the Fluctuations of the Mutual Information for Non Centered MIMO Channels: The Non Gaussian Case", IEEE SPAWC, Marrakech, Morocco, June 2010.
D. Gregoratti, W. Hachem and X. Mestre, "Orthogonal Matrix Precoding for Relay Networks", IEEE ISWPC, Modena, Italy, May 2010.
E. Bouton, N. Ksairi, P. Ciblat, P. Bianchi and W. Hachem, "On outage probability optimization in Rician MISO channels" IEEE WiMob, Marrakech, Morocco, October 2009.
N. Ksairi, P. Ciblat, P. Bianchi et W. Hachem, "Compromis diversité-multiplexage pour un protocole de relayage DF non-orthogonal", accepté au colloque GRETSI, Dijon (France), Septembre 2009.
N. Ksairi, P. Bianchi, Ph. ciblat and W. Hachem, "A Static Protocol to Achieve Optimal Diversity-Multiplexing Tradeoff for High Diversity Gains in Half-Duplex Relay Channels", accepted in ITW 2009, Taormina, Italy.
M. Nahas, A. Saadani and W. Hachem, "Performance of Asynchronous Amplify-and-Forward Cooperative Relay Networks", Globecom 2009.
W. Hachem, E. Moulines, J. Najim and F. Roueff, "On the Error Exponents for Detecting Randomly Sampled Noisy Diffusion Processes" ICASSP 2009, Taipei, Taiwan.
N. Ksairi, P. Bianchi, W. Hachem and Ph. Ciblat, "Resource Allocation for Downlink OFDMA 2D-Cellular Networks with partial frequency reuse", ISITA 2008, Auckland, New Zealand.
P. Bianchi, Ph. Ciblat and W. Hachem, "Outage Performance of a Novel Relaying Protocol: Decode or Quantize and Forward", ISITA 2008, Auckland, New Zealand.
M. Nahas, A. Saadani and W. Hachem, "On the Outage Probability of Asynchronous Wireless Cooperative Networks", VTC Fall 2008.
A. Kammoun, M. Kharouf, W. Hachem and J. Najim, "Fluctuations of the SNR at the Wiener Filter Output for Large Dimensional Signals", SPAWC 2008.
A. Kammoun, M. Kharouf, W. Hachem and J. Najim, "Outage Probability Approximation for the Wiener Filter SINR in MIMO Systems", SPAWC 2008.
N. Ksairi, P. Bianchi, Ph. Ciblat, and W. Hachem, "Optimal Reuse Factor and Resource Allocation for Downlink OFDMA with Multicell Interference", SPAWC 2008.
W. Hachem, P. Bianchi and Ph. Ciblat, "Outage Probability Optimization of Certain Wireless Relaying Protocols", ITW 2008.
W. Hachem, Ph. Loubaton and J. Najim, "On the Fluctuations of the Mutual Information of Large Dimensional MIMO Channels", ITW 2008.
W. Hachem, Ph. Loubaton et J. Najim, " Sur les fluctuations de l'information mutuelle des canaux MIMO de grandes dimensions ", Colloque GRETSI 2007, Troyes, France.
J. Dumont, W. Hachem, S. Lasaulce, Ph. Loubaton et J. Najim, " Quelques propriétés d'un approximant de l'information mutuelle des canaux MIMO de Rice bi-corrélés ", Colloque GRETSI 2007, Troyes, France.
J. Dumont, W. Hachem, S. Lasaulce, Ph. Loubaton and J. Najim, "High SNR approximations of the capacity of MIMO correlated Rician channels: a large system approach", ISIT'2007, Nice, France.
S. Gault, W. Hachem and Ph. Ciblat, "Performance of a Resource Allocation Strategy for an FH-OFDMA based System in a multi-cell environment", SPAWC'2006, Cannes, France.
A.M. Cipriano, Ph. Ciblat, S. Gault and W. Hachem, "Balanced allocation strategy in multi-user OFDM with Channel State Information at the transmitter", EUSIPCO'2006, Florence, Italy.
W. Hachem, Ph. Loubaton and J. Najim, "The Mutual Information of a MIMO Channel: A Survey", ISCCSP'2006, Marrakech, Morocco.
J. Dumont, W. Hachem, Ph. Loubaton and J. Najim, "On the Asymptotic Analysis of Mutual Information of MIMO Rician Correlated Channels", ISCCSP'2006, Marrakech, Morocco.
S. Gault, Ph. Ciblat, and W. Hachem, "An OFDMA Based Modem for Powerline Communication Over the Low Voltage Distribution Network", ISPLC'2005, Vancouver, Canada.
J. Fiorina and W. Hachem, "Trade-off between repetition factor and frame length in Time-Hopping Impulse Radio Ultra Wide Band", PIMRC'2005, Berlin, Germany.
J. Fiorina and W. Hachem, "Central Limit Results for the Multiple User Interference at the SUMF Output for UWB Signals", ISITA'2004, Parma, Italy.
B. Mouhouche, Ph. Loubaton and W. Hachem, "Asymptotic Analysis of Reduced Rank Chip-Level MMSE Equalizers in the Downlink of CDMA Systems", SPAWC'2004, Lisboa, Portugal.
B. Mouhouche, Ph. Loubaton, W. Hachem and N. Ibrahim, "Asymptotic Analysis of Reduced Rank Downlink CDMA Wiener Receivers", EUSIPCO'2004, Vienna, Austria.
A. Wautier, S. Ammari and W. Hachem, "Low Complexity Linear Detection for Asynchronous CDMA Signals Over Frequency Selective Channels", EUSIPCO'2004, Vienna, Austria.
S. Gault, W. Hachem and Ph. Ciblat, "Cramér-Rao Bounds for Data-Aided Sampling Clock Offset and Channel Estimation",ICASSP'2004, Montreal, Canada.
B. Mouhouche, P. Loubaton, W.Hachem, K. Abed-Meraim et N. Ibrahim, "Analyse asymptotique de certains filtres de Wiener à rang réduit", proposé au colloque GRETSI'2003, Paris.
Ph. Loubaton and W. Hachem, "Asymptotic Analysis of Reduced Rank Wiener Filters", ITW'2003, Paris, France.
W. Hachem, "Low Complexity Polynomial Receivers for Downlink CDMA", Asilomar Conference on Signals, Systems and Computers 2002, Pacific Grove, California.
L. Ouvry , W. Hachem, D. Lattard, M. Laugeois, B. Piaget, "A DSSS-CDMA Based Implementation For Powerline Communications", WTC'02, Paris, France.
J.-M. Chaufray, Ph. Loubaton and W. Hachem, "Asymptotical Analysis of Optimum and Sub-Optimum CDMA Downlink MMSE Receivers", ISIT'2002, Lausanne.
M. Debbah, W. Hachem, Ph. Loubaton and Marc de Courville, "Asymptotic Performance Analysis for Redundant Block Precoded OFDM Systems with MMSE Equalization", SSP'2001, Singapore, October 2001.
M. Debbah, W. Hachem, Ph. Loubaton and Marc de Courville, "MMSE Analysis of Certain Large Isometric Random Precoded Systems", ITW'2001, Cairns, Australia, September 2001.
W. Hachem, Ph. Loubaton, S. Marcos and R. Samy, "Multiple Access Communication Over the PowerLine Channel: a CDMA Approach", GLOBECOM'01, San Antonio, Texas, November 2001.
W. Hachem, F. Desbouvries and Ph. Loubaton, "Blind Channel Estimation for CDMA Systems: An Induced Cyclostationarity Approach", ICASSP'2000, Istanbul, Turkey, June 2000.
W. Hachem, F. Desbouvries and Ph. Loubaton, "Un algorithme d'identification autodidacte multi entrée / multi sortie en présence de bruit corrélé spatialement", Actes du Colloque GRETSI'99, Vannes, France, September 1999.
W. Hachem, F. Desbouvries and Ph. Loubaton, "On the Identification of Certain Noisy FIR Convolutive Mixtures", ICA'99, Aussois, France, January 1999.

PRESENTATIONS

A mini course on the "Applications of Large Random Matrices to Digital Communications and Statistical Signal Processing" given at EUSIPCO 2011, Barcelona, with Ph. Loubaton and J. Najim.

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