信息学院学术报告

报告内容摘要:  Multiple Input Multiple Output (MIMO) systems have beenemerged as a

new paradigm in wireless communications due to theirenormous capacity gains

predicted by recent theoretical researchers.However, the majority work of the MIMO

channel capacity assumes that the MIMO fading channels are frequency flat and time

quasi-static, that means the fading channels have neither intersymbol interference

(ISI) nor Doppler spread, which is not the case in many practical wireless systems

with high data rate and user mobility. 

In this talk, we will consider realistic MIMO channels undergoing triply

selective fading, that is, space-selective, time-selective and frequency-selective

fading. We demonstrate that, besides spatial and temporal correlations, there

exists ISI inter-tap correlations due to

irregular delay spreads in frequency-selective fading. This ISI inter-tap

correlation has been largely overlooked but it has significant impact on channel

capacity and transceiver design. We will present both theoretical and simulation

results for the ergodic capacity and outagecapacity of MIMO triply selective

fading channels. Our results show that (1) the frequency-selective channel usually

have smaller ergodic capacity than frequency flat channel, which is different from

the established results in the literature; (2) although time variation has no

influence on ergodic capacity, it has significant impact on the outage capacity;

(3) MIMO channels have four-dimensional diversities which consist of transmit,

receive, Doppler and multipath diversities.

报告人简介：

Chengshan Xiao received the B.S. degree from the University of Electronic Science

and Technology of China (UESTC), Chengdu, China, in 1987, the M.S. degree from

Tsinghua University, Beijing, China, in 1989,and Ph.D. degree from the University

of Sydney, Australia, in 1997, all in electronic engineering.

Dr. Xiao was a lecturer at Tsinghua University, a Senior Member ofScientific Staff

at Nortel Networks at Ottawa, Canada, and an Assistant

Professor at the University of Alberta, Canada. He is currently a faculty member

at the University of Missouri-Columbia, Missouri, USA.

Dr. Xiao's research interests include wireless communications, signal

processing, multidimensional and multirate systems, and nonlinearcontrol. He has

published more than 80 papers in international journals and conferences. He holds

3 US patents in wireless communications area.Two of his algorithms have been

implemented into Nortel's base station radios with successful technical field

trials and network integration.

Dr. Xiao is an Associate Editor for the IEEE TRANSACTIONS ON WIRELESS

COMMUNICATIONS, and the IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY. Previously, he

was an Associate Editor for the IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS-I, and

the International Journal of MULTIDIMENSIONAL SYSTEMS AND SIGNAL PROCESSING. He is

currently the Vice Chair of Technical Committee on Personal Communications (TCPC)

of IEEE Communications Society.