November 11, 2016, Benoit Champagne, McGill University

Friday, November 11, 2016, 3-4pm
8 St. Mary’s Street, PHO 210
Refreshments at 2:45pm

Benoit Champagne
McGill University

Secure MIMO AF Relaying Design Under Imperfect Eavesdropper CSI: A Robust Optimization Framework

The broadcast nature of wireless propagation has posed significant challenges on the design of secure communications in the presence of unauthorized users, i.e., eavesdroppers, which try to retrieve information from an ongoing transmission without being detected. Against this background, physical layer security, which exploits signal processing techniques and wireless channel characteristics to enhance the transmission security, has received considerable interest in recent years as a complement to traditional encryption techniques. In this talk, we address the problem of secure amplify-and-forward (AF) relaying for multiple-input multiple-output (MIMO) relaying networks in the presence of multiple eavesdroppers. The emphasis is on a practical setting where only imperfect eavesdropper channel state information (ECSI) is available. A robust optimization framework is developed for the secure AF relay design where the general aim is to maximize the signal-to-interference-plus-noise ratio (SINR) at the destination under transmit power and secrecy constraints. The proposed framework covers three different types of models for the ECSI errors, that is: (1) deterministic norm-bounded; (2) random with Gaussian distribution; and (3) random with unknown distribution (i.e., known 1^st and 2^nd order moments). In each case, the resulting optimization problem for the AF relaying matrix design becomes non-convex. Suitable transformations and/or approximation techniques (e.g., S-procedure, difference of convex functions, semi-definite relaxation, etc.) are applied to develop efficient algorithmic solutions. The improved secrecy of the proposed transceiver designs against eavesdropping and their robustness to ECSI uncertainties are demonstrated through extensive numerical simulations.

Benoit Champagne received the B.Ing. degree in Engineering Physics from École Polytechnique de Montréal in 1983, the M.Sc. degree in Physics from the Université de Montréal in 1985, and the Ph.D. degree in Electrical Engineering from the University of Toronto in 1990. From 1990 to 1999, he was an Assistant and then Associate Professor at INRS-Telecommunications, Université du Québec, Montreal. In 1999, he joined McGill University, Montreal, where he is now a Full Professor in the Department of Electrical and Computer Engineering; he also served as Associate Chairman of Graduate Studies in the Department from 2004 to 2007. His research focuses on the study of advanced algorithms for the processing of communication signals by digital means. His interests span many areas of statistical signal processing, including detection and estimation, sensor array processing, adaptive filtering, and applications thereof to wireless communications and audio processing, where he has co-authored nearly 250 refereed publications. His research has been funded by the Natural Sciences and Engineering Research Council (NSERC) of Canada, the Fonds de Recherche sur la Nature et les Technologies from the Govt. of Quebec, as well as some major industrial sponsors, including Nortel Networks, Bell Canada, InterDigital and Microsemi. He has been an Associate Editor for the EURASIP J. on Applied Signal Processing (2005–2007), the IEEE Signal Processing Letters (2006–2008), and the IEEE Trans. on Signal Processing (2010–2012), as well as a Guest Editor for two special issues of the EURASIP J. on Applied Signal Processing. He has also served on the Technical Committees of several international conferences in the fields of communications and signal processing. In particular, he was Registration Chair, for IEEE ICASSP 2004, Co-Chair, Antenna and Propagation Track, for IEEE VTC–Fall 2004, Co-Chair, Wide Area Cellular Communications Track, for IEEE PIMRC 2011, Co-Chair, Workshop on D2D Communications, for IEEE ICC 2015 and Publicity Chair, for IEEE VTC–Fall 2016. His is currently a Senior Member of IEEE.

Faculty Host: Janusz Konrad
Student Host: Tingting Xu