

CNRS / LIGM (UMR 8049)
Université Gustave Eiffel
Bât. Copernic,
bureau 4B190.
5, blvd. Descartes,
ChampssurMarne,
77454, MarnelaVallée Cedex 2.
France.
Email:
firstname
(dot) lastname
(at) univeiffel (dot) fr
Useful links:


Walid Hachem
Researcher at the Centre national de la recherche scientifique
(CNRS).
Université Gustave Eiffel
Laboratoire d'informatique Gaspard Monge (LIGM)
Equipe Méthodes et modèles pour le signal, les images et les données
(MMSID)
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 Paris in 1990, the PhD in signal processing
from Université
ParisEst MarnelaVallée (now part of Université Gustave
Eiffel) in 2000 and the "Habilitation à
diriger des recherches" from Université ParisSud (now part of
Université Paris Saclay) in 2006. Between
1990 and 2000, I worked in the telecommunications industry 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 a
research director. After being based at Telecom Paris
between 2006 and 2016, I am now a CNRS member of the laboratoire d'informatique Gaspard Monge (LIGM) at the
Gustave Eiffel University.
My research and teaching activities are devoted to the mathematical tools for
signal processing and statistical estimation. My research themes mainly
consist in the large random matrix theory and its applications in the above
fields, in the optimization algorithms in random environments, and more
recently, in the large dimensional probability applied to the mathematical
biology and ecology.

Publications
JOURNAL PAPERS

P. Bianchi, W. Hachem, and V. Priser,
Long run convergence of discretetime interacting particle
systems of the McKeanVlasov type
, Preprint, March 2024.

M.Y. Gueddari, W. Hachem, and J. Najim,
Elliptic Approximate Message Passing and an application to theoretical ecology
, Preprint, February 2024.

W. Hachem,
Approximate Message Passing for sparse matrices with application
to the equilibria of large ecological LotkaVolterra systems
,
Stochastic Processes and their Applications, in press (December 2023).

I. Akjouj, W. Hachem, M. Maïda, and J.Najim
Equilibria of large random LotkaVolterra systems with vanishing species:
a mathematical approach
,
Preprint, July 2023.

I. Akjouj, M. Barbier, M. Clenet, W. Hachem, M. Maïda, F. Massol, J.Najim,
and V.C. Tran,
Complex systems in Ecology: a guided tour with large LotkaVolterra models
and random matrices,
Proceedings of the Royal Society A: Mathematical, Physical and
Engineering Sciences, in press (December 2023).
Supplementary material.

A. Bose and W. Hachem,
Spectral measures of empirical autocovariance matrices of high dimensional
Gaussian stationary processes,
Random Matrices, Theory and Applications, 12 (2), 2023.

P. Bianchi, W. Hachem, and Sh. Schechtman,
Stochastic subgradient descent escapes Active Strict Saddles
on weakly convex functions,
to be published in Mathematics of Operations Research (July 2023).

A. Barakat, P. Bianchi, W. Hachem, and Sh. Schechtman,
Stochastic optimization with momentum:
convergence, fluctuations, and traps avoidance,
Electronic Journal of Statistics,
2021, Vol. 15, No. 2, 38923947.

N. Cook, W. Hachem, J. Najim, and D. Renfrew,
NonHermitian random matrices with a variance profile (II):
properties and examples,
Journal of Theoretical Probability, (2022) 35:23432382.

P. Bianchi, W. Hachem, and Sh. Schechtman,
Convergence of constant step stochastic gradient descent
for nonsmooth nonconvex functions ,
SetValued and Variational Analysis, 30, pages 11171147 (2022).

P. Bianchi, W. Hachem, and A. Salim
A fully stochastic primaldual algorithm,
Optimization Letters, 15, 701710 (2021).

A. Bose and W. Hachem,
Smallest singular value and limit eigenvalue distribution of a
class of nonHermitian random matrices with statistical application,
Journal of Multivariate Analysis, 178, July 2020.

W. Hachem, A. Hardy, and S. Shamai,
Mutual Information of Wireless Channels and BlockJacobi Ergodic Operators,
IEEE Transactions on Information Theory, 65 (11), Pages 71497167,
November 2019.

A. Salim, P. Bianchi, and W. Hachem,
Snake: a Stochastic Proximal Gradient Algorithm for
Regularized Problems over Large Graphs,
IEEE Transactions on Automatic Control, 64 (5), Pages 18321847,
May 2019.

P. Bianchi, W. Hachem, and A. Salim,
A constant step ForwardBackward algorithm involving random maximal
monotone operators,
Journal of Convex Analysis, 26 (2), Pages 397436, 2019.

N. Cook, W. Hachem, J. Najim, and D. Renfrew,
NonHermitian random matrices with a variance profile (I): deterministic
equivalents and limiting ESDs.,
Electronic Journal of Probability, Volume 23, (2018).

P. Bianchi, W. Hachem, and A. Salim,
Constant Step Stochastic Approximations Involving Differential Inclusions:
Stability, LongRun Convergence and Applications
, Stochastics, 91 (2), Pages 288320, 2019.

P. Bianchi and W. Hachem,
Dynamical behavior of a stochastic forwardbackward algorithm using
random monotone operators,
Journal of Optimization Theory and Applications,
171: 90120, 2016.

W. Hachem, A. Hardy and J. Najim,
A Survey on the Eigenvalues Local Behavior of
Large Complex Correlated Wishart Matrices,
ESAIM: Proceedings and Surveys, (51) 150174, October 2015.

W. Hachem, A. Hardy and J. Najim,
Large Complex Correlated Wishart Matrices:
The Pearcey Kernel and Expansion at the Hard Edge,
Electronic Journal of Probability, 21 (2016).

W. Hachem, A. Moustakas and L. Pastur,
The Shannon's mutual information of a multiple antenna time
and frequency dependent channel: an ergodic operator approach,
Journal of Mathematical Physics, 56 (11), November 2015.

W. Hachem, A. Hardy and J. Najim,
Large Complex Correlated Wishart Matrices: Fluctuations and Asymptotic
Independence at the Edges,
Annals of Probability, 44 (3), pages 22642348, 2016.

P. Bianchi, W. Hachem and F. Iutzeler,
A Coordinate Descent PrimalDual Algorithm and Application to Distributed
Asynchronous Optimization
, IEEE Transactions on Automatic Control, 61 (10),
pages: 29472957, 2016.

J. Vinogradova, R. Couillet, and W. Hachem,
Estimation of Toeplitz covariance matrices in large dimensional regime with
application to source detection,
IEEE Transactions on Signal Processing, 63 (18), pages 49034913,
September 2015.

F. Iutzeler, P. Bianchi, Ph. Ciblat, and W. Hachem,
"Explicit Convergence Rate of a Distributed Alternating Direction
Method of Multipliers"
, IEEE Transactions on Automatic Control,
61 (4), pages 892  904, 2016.

R. Couillet and W. Hachem,
"Analysis of the limiting spectral measure of large random matrices of the
separable covariance type" (with a correction in the proof of Lemma 3.3),
Random Matrices: Theory and Applications 03 (04), 2014.

J. Vinogradova, R. Couillet and W. Hachem,
"Statistical Inference in Large Antenna Arrays
under Unknown Noise Pattern",,
IEEE Transactions on Signal Processing, 61 (22), 2013, pages 56335645.

F. Chapon, R. Couillet, W. Hachem and X. Mestre,
"The outliers among the singular values of large rectangular random matrices
with additive fixed rank deformation"
, Markov Processes and Related Fields, 20, 183228 (2014).

P. Bianchi, G. Fort and W. Hachem,
"Performance of a Distributed Stochastic Approximation Algorithm",
IEEE Transactions on Information Theory, 59 (11), Pages 74057418,
2013.

F. Iutzeler, Ph. Ciblat and W. Hachem,
"Analysis of SumWeightlike algorithms
for averaging in Wireless Sensor Networks"
, IEEE Transactions on Signal Processing,
Vol. 61, No. 11, Pages 2802  2814, 2013.

W. Hachem, Ph. Loubaton, X. Mestre, J. Najim and P. Vallet,
"A Subspace Estimator for Fixed Rank Perturbations of Large Random Matrices"
, Journal of Multivariate Analysis,
Vol. 114, February 2013, Pages 427447.

R. Couillet and W. Hachem,
"Fluctuations of spiked random matrix models and failure diagnosis
in sensor networks",
IEEE Transactions on Information Theory,
Vol. 59, No. 1, Pages 509525, 2013.

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, Vol. 49, No. 1 (2013), pages 3663.

F. Rubio, X. Mestre and W. Hachem,
"A CLT on the SNR of diagonally loaded MVDR filters",
IEEE Transactions on Signal Processing,
Vol. 60, No. 8, pages 41784195, August 2012.

N. Ksairi, Ph. Ciblat, P. Bianchi, and W. Hachem,
"Performance Analysis over Slow Fading Channels of a HalfDuplex SingleRelay
Protocol: Decode or Quantize and Forward",
IEEE Transactions on Communications,
Vol. 60, No. 7, pages 20092016, July 2012
(long version with proofs).

W. Hachem, M. Kharouf, J. Najim and J.W. Silverstein,
"A CLT for Informationtheoretic statistics of Noncentered Gram random
matrices" ,
Random Matrices: Theory and Applications, 01 (02), April 2012.

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",
Random Matrices: Theory and Applications, 01 (02), April 2012.

D. Gregoratti, W. Hachem and X. Mestre,
"Randomized Isometric LinearDispersion SpaceTime Block Coding for the
DF Relay Channel",
IEEE Transactions on Signal Processing, Vol. 60, No. 1, pages 426442,
January 2012.

W. Hachem, E. Moulines and F. Roueff,
"Error exponents for NeymanPearson detection of a continuoustime Gaussian
Markov process from noisy irregular samples",
IEEE Transactions on Information Theory,
Vol. 57 , No. 6 Page(s) 38993914, June 2011.

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. 10481069, March 2010.

M. Nahas, A. Saadani and W. Hachem,
"Performance of Asynchronous TwoRelay TwoHop Wireless Cooperative Networks",
IEEE Transactions on Wireless Communications, Vol. 9, No. 3, March 2010.

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.

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 43864397,
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 50485063,
November 2009.

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 764782,
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), 20712130.

W. Hachem, O. Khorunzhiy, Ph. Loubaton, J. Najim, and L. Pastur, "A New Approach for Capacity Analysis of Large Dimensional MultiAntenna Channels", IEEE Transactions on Information Theory,
Vol. 54, No. 9, September 2008, 39874004.

S. Sezginer, P. Bianchi, and W. Hachem, "Asymptotic CramérRao Bounds and Training Design for MIMOOFDMA 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 MultiCell 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 ReducedRank ChipLevel MMSE Equalizers in the
Downlink of CDMA Systems",
IEEE Transactions on Signal Processing,
55 (6), pages 30483060, June 2007.

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 649670, 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 TimeHopped UWB Signals", IEEE Transactions on Signal Processing, July 2006.

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,
"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 SubOptimum 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 12931311, 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 651661, March 2002.
 W. Hachem, F. Desbouvries and Ph. Loubaton,
"Identification of certain noisy MA models: new results ", System and Control Letters, 39, 2000, pages 237243.
CONFERENCE PAPERS

M.Y. Gueddari, W. Hachem and J. Najim,
A Linear Complementarity Problem based on nonSymmetric Large Random Matrices
,
GRETSI 2023, Grenoble, France.

W. Hachem,
"Les grandes matrices aléatoires : un aperçu historique",
GRETSI 2022, Nancy, France. Présentation.

W. Hachem et J. Najim,
"Approximate Message Passing et solutions de grands systèmes dynamiques
écologiques de LotkaVolterra",
GRETSI 2022, Nancy, France.

A. Bose and W. Hachem,
"A whiteness test based on the spectral measure of large nonHermitian
random matrices", ICASSP 2020, Barcelona, Spain.
Slides.

H. Nikbacht, M. Wigger, W. Hachem and Sh. Shamai (Shitz),
"Mixed Delay Constraints on a Fading CRAN Uplink",
ITW 2019, Visby, Gotland, Sweden.

W. Hachem, A. Hardy et Sh. Shamai (Shitz),
"Information mutuelle de canaux radio et opérateurs de Jacobi ergodiques",
GRETSI 2019, Lille, France.
Présentation.

A. Salim, P. Bianchi, and W. Hachem,
"A Constant Step Stochastic DouglasRachford Algorithm with Application to Non
Separable Regularizations", ICASSP 2018, Calgary, Canada.

A. Salim, P. Bianchi, and W. Hachem,
"Convergence d'un algorithme du gradient proximal stochastique
à pas constant et généralisation aux opérateurs monotones aléatoires",
GRETSI 2017, JuanlesPins, France.

A. Salim, P. Bianchi, and W. Hachem,
"Snake: a Stochastic Proximal Gradient Algorithm for
Regularized Problems over Large Graphs",
CAP 2017, Grenoble, France.

C. Meillier, P. Bianchi, and W. Hachem,
"Two distributed algorithms for the deconvolution of
large radiointerferometric multispectral images",
EUSIPCO 2016, Budapest, Hungary.

A. Salim, P. Bianchi, W. Hachem and J. Jakubowicz,
"A Stochastic Proximal Point Algorithm for Total Variation Regularization over Large Scale Graphs",
IEEE CDC 2016, Las Vegas, USA.
Accompanying document.

P. Bianchi, W. Hachem and A. Salim,
"Building Stochastic Optimization Algorithms with Random Monotone Operators",
European Conference on Computational Optimization (EUCCO) 2016,
Leuven, Belgium.

W. Hachem, A.L. Moustakas and L.A. Pastur,
"Time and frequency selective Ricean MIMO
capacity: an ergodic operator approach",
IEEE ISIT 2016, Barcelona, Spain.

X. Mestre, P. Vallet and W. Hachem,
"Asymptotic Analysis of Linear Spectral Statistics of the Sample Coherence
Matrix",
IEEE ICASSP 2015.

P. Bianchi W. Hachem and F. Iutzeler,
"Linear Convergence of an Asynchronous Distributed Optimization Algorithm
based on the Alternating Direction Method of Multipliers",
IEEE GlobalSIP 2014, Atlanta, USA.

P. Bianchi, W. Hachem and F. Iutzeler
"A Stochastic Coordinate Descent PrimalDual Algorithm And Applications",
IEEE MLSP 2014, Reims, France.

P. Bianchi and W. Hachem,
"A PrimalDual Algorithm for Distributed Optimization",
IEEE Conference on Decision and Control 2014, Los Angeles, USA.

F. Iutzeler, P. Bianchi, Ph. Ciblat, and W. Hachem,
"Linear Convergence Rate for Distributed Optimization with the Alternating
Direction Method of Multipliers",
IEEE Conference on Decision and Control 2014, Los Angeles, USA.

J. Vinogradova, R. Couillet, and W. Hachem,
"Estimation of large Toeplitz covariance matrices and application to
source detection", EUSIPCO 2014, Lisbon, Portugal.

X. Mestre, P. Vallet, and W. Hachem,
"Correlation Test for High Dimensional Data with Application to Signal
Detection in Distributed Sensor Networks", EUSIPCO 2014, Lisbon, Portugal.

F. Iutzeler, P. Bianchi, Ph. Ciblat and W. Hachem,
"Asynchronous Distributed Optimization using a Randomized Alternating
Direction Method of Multipliers",
IEEE Conference on Decision and Control 2013, Florence, Italy.

J. Vinogradova, R. Couillet and W. Hachem,
"A new method for source detection, power estimation, and localization in
large sensor networks under noise with unknown statistics"
,
IEEE ICASSP 2013.

J. Vinogradova, R. Couillet, W. Hachem,
"Nouvelle méthode de détection de sources, d'estimation de
puissances et de localisation dans un système de communication sans
fil avec des statistiques de bruit inconnues",
Actes du colloque GRETSI, 2013.

F. Iutzeler, P. Ciblat, W. Hachem, and J. Jakubowicz,
New broadcast based distributed averaging algorithm over wireless sensor
networks,
IEEE ICASSP 2012.

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 RobbinsMonro distribué",
GRETSI 2011, Bordeaux, France.

F. Iutzeler, Ph. Ciblat, W. Hachem, et J. Jakubowicz,
"Estimation distribuée du maximum dans un réseau de capteurs",
GRETSI 2011, Bordeaux, France.

P. Bianchi, G. Fort, W. Hachem, and J. Jakubowicz,
"Performance Analysis of a Distributed RobbinsMonro Algorithm for Sensor
Networks", EUSIPCO 2011, Barcelona, Spain.

P. Vallet, W. Hachem, P. Loubaton, X. Mestre and J.Najim,
"On the Consistency of the GMUSIC DoA Estimator",
SSP 2011, Nice, France.

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, France.

X. Mestre, P. Vallet, P. Loubaton, and W. Hachem,
"Asymptotic Analysis of a Consistent Subspace Estimator for Observations of
Increasing Dimensions", SSP 2011, Nice, France.

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,
Czech Republic.

F. Rubio, X. Mestre and W. Hachem,
"A CLT on the SINR of the Diagonally Loaded Capon/MVDR Beamformer,
ICASSP 2011, Prague, Czech Republic.

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 diversitémultiplexage pour un protocole de relayage
DF nonorthogonal",
accepté au colloque GRETSI, Dijon (France), Septembre 2009.

N. Ksairi, P. Bianchi, Ph. ciblat and W. Hachem,
"A Static Protocol to Achieve Optimal DiversityMultiplexing Tradeoff for
High Diversity Gains in HalfDuplex Relay Channels", accepted in
ITW 2009, Taormina, Italy.

M. Nahas, A. Saadani and W. Hachem,
"Performance of Asynchronous AmplifyandForward 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 2DCellular 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 bicorrélés ", 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 FHOFDMA based System in a multicell environment",
SPAWC'2006, Cannes, France.

A.M. Cipriano, Ph. Ciblat, S. Gault and W. Hachem,
"Balanced allocation strategy in multiuser 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,
"Tradeoff between repetition factor and frame length in TimeHopping
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 ChipLevel 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,
"CramérRao Bounds for DataAided Sampling Clock Offset and Channel Estimation",ICASSP'2004, Montreal, Canada.
 B. Mouhouche, P. Loubaton, W.Hachem, K. AbedMeraim 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 DSSSCDMA Based Implementation For Powerline Communications",
WTC'02, Paris, France.
 J.M. Chaufray, Ph. Loubaton and W. Hachem,
"Asymptotical Analysis of Optimum and SubOptimum 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.
Some presentations
Information mutuelle de canaux radio et opérateurs de Jacobi ergodiques,
GRETSI,
Lille, août 2019.
Spectres de grandes matrices aléatoires non hermitiennes :
bases et quelques applications,
Journées MAS,
Dijon, août 2018.
Opérateurs monotones maximaux et approximation stochastique,
GdR ISIS, journée sur l'optimisation en milieu aléatoire,
Paris, novembre 2017.
The mutual information of a MIMO noncentered time and frequency selective
channel: an ergodic operator approach,
Random matrix theory and statistical physics workshop,
Institut Henri Poincaré, Paris, November 2014.
Grandes matrices aléatoires de Wishart :
fluctuations et indépendance asymptotique aux bords du spectre,
Journées MAS,
Toulouse, septembre 2014.
Asynchronous distributed optimization using a randomized ADMM algorithm,
November 2013.
Fixed Rank Perturbations of Large Random Matrices:
Methodology and Some Statistical Applications,
Institut Henri Poincaré, Paris, March 2012.
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.
LIGM
orcid.org/0000000184992761
