Semidefinite relaxation (SDR) has recently been recognized as a key technique in signal processing and communications. It is a powerful approximation technique for a host of difficult optimization problems, notably nonconvex quadratically constrained quadratic programs. SDR has found numerous applications; among them particularly important applications are MIMO detection (which covers multi-user, multi-antenna, space-time,…), transmit beamforming (which covers classical single-cell multiuser downlinks, multicell coordinated multiuser downlinks, unicasting and multicasting, cognitive radio, physical layer security, one-way and two-way relays…), and source localization (which covers TOA, TDOA, sensor network localization,…). And the application scope is still expanding. This talk aims at giving an overview of SDR. I will describe essential ideas and practical deployment aspects of SDR, and summarize some of the key theoretical results offered by optimization researchers, which will be presented from a non-expert viewpoint. And certainly, the talk will cover the important SDR applications, and some very forefront advances in those applications.
Wing-Kin Ma received the B.Eng. degree in electrical and electronic engineering from the University of Portsmouth, Portsmouth, U.K., in 1995 and the M.Phil. and Ph.D. degrees, both in electronic engineering, from the Chinese University of Hong Kong (CUHK), Hong Kong, in 1997 and 2001, respectively. He is currently an Assistant Professor with the Department of Electronic Engineering, CUHK. From 2005 to 2007, he was also an Assistant Professor with the Institute of Communications Engineering, National Tsing Hua University, Taiwan, R.O.C. Prior to that, he held various research positions with McMaster University, Canada; CUHK; and the University of Melbourne, Australia. His research interests are in signal processing and communications, with a recent emphasis on MIMO communication, convex optimization, blind source separation, and signal processing for hyperspectral remote sensing. Dr. Ma is currently Associate Editor of IEEE Signal Processing Letters, and Guest Editor of IEEE Journal of Selected Areas in Communications on the special issue “Signal Processing Techniques for Wireless Physical Layer Security.” He previously served as Associate Editor of IEEE Transactions on Signal Processing, and Guest Editor of IEEE Signal Processing Magazine. He was a Speaker of a Tutorial in EUSIPCO 2011. He is a recipient of the 2009 Exemplary Teaching Award given by the Faculty of Engineering, CUHK, and co-recipient of an ICASSP 2011 Best Student Paper Award and a WHISPERS 2011 Best Paper Award.