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Home | Seminars and Symposia | Past seminars/symposia: Wednesday, April 24, 2002

DTC Seminar Series

Achieving Near Capacity for MIMO Wireless Channels Using Soft Quasi-Maximum-Likelihood Detection


Zhi-Quan (Tom) Luo
Department of Electrical and Computer Engineering
McMaster University, Canada

Wednesday, April 24, 2002
9:00 am

402 Walter Library

Recent advancements in iterative processing of channel codes have made it possible to achieve near-capacity for a single antenna wireless fading channel with low complexity. In this talk, we show that these techniques, when combined with a new soft Quasi-Maximum-Likelihood detector, can also achieve near-capacity of a multiple-antenna wireless channels. This soft Quasi-ML detector maximizes the log-likelihood function by deploying a semi-definite relaxation (SDR) and is shown (theoretically and empirically) to provide high quality approximation to the optimal ML detector performance. Compared to the existing Sphere Decoder approach, the new Quasi-ML approach enjoys low polynomial worst case complexity, as well as guaranteed near optimal detection performance. We consider both Turbo and Low-Density-Parity Check codes and show that excellent performance can be attained at high data rates.


Zhi-Quan (Tom) Luo received his B.Sc. degree in Applied Mathematics in 1984 from Peking University, Beijing, China. Subsequently, he was selected by a joint committee of American Mathematical Society and the Society of Industrial and Applied Mathematics to pursue Ph.D study in the United States. After one-year intensive training in Mathematics and English at the Nankai Institute of Mathematics, Tianjin, China, he was admitted to the Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, where he received the Ph.D degree in 1989. Upon graduation, he joined the Department of Electrical and Computer Engineering, McMaster University, Hamilton, Canada, where he is now the department head and holds a Canada Research Chair in Information Processing. His research interests include the algorithmic/complexity issues arising from data communication, information theory and coding, wireless and optical networks and systems, and signal processing. He currently serves on the editorial boards for a number of international journals including SIAM Journal on Optimization, IEEE Transactions on Signal Processing.