题　目：Space Time Coding with Bandwidth-Limited Feedback

报告人：王海泉博士（加拿大滑铁卢大学电气与计算机工程系博士后）

时　间：11月29日（周四）下午2点

地　点：信电楼四楼学术厅

欢迎广大师生踊跃参加！

Abstract

In this presentation, I will give some basic coding criteria for a Multiple-Input, Multiple-Output (MIMO) system with bandwidth-limited feedback.

In a MIMO system, coded signals are spread on multiple paths and at different time slots by using multiple antennas and time delay slots. Thus, multiple independently faded replicas of the same data will reach various receiver antennas at different time slots, yielding “space diversity” and “time diversity”. To effectively utilize space diversity and time diversity, “Space Time” codes have been well studied. For a MIMO system without feedback, designing criteria for a space time code have been introduced based on the pair-wise error probability analysis. Being guided by these criteria, many excellent space time codes have been constructed in recent years. Yet, studies on code design for MIMO systems with bandwidth-limited feedback are novel and promising.

Consider a MIMO system with an error-free, zero-delay, and bandwidth-limited feedback channel. Intuitively, the receiver should use this feedback channel to send some information such as channel states back to the transmitter so that the transmitter may utilize such information to code and transmit signals in a more efficient way. Specifically, there are two problems to be tackled as follow: (1) on the receiver side, how to select channel information to be sent back? (2) on the transmitter side, how to do the coding, i.e., how to utilize the channel information to effectively exploit the space and time diversities for designing codes such that the performance of the whole system can be improved?

We will discuss some basic criteria for solving the two problems above. At first, it is shown that, based on performance analysis, the first problem is equivalent to the following issues: (i) how to divide a Stiefel manifold into finite parts; (ii) how to divide a cone into finite parts. Furthermore, criteria for the above are established and detail methods based on the criteria are illustrated. Secondly, designing criteria for the problem (2) are also derived and detail designing methods based on the criteria are described. Finally, designing examples and simulations are given.

Biography

Haiquan Wang, post-doctoral fellow, Department of Electrical and Computer Engineering, University of Waterloo, Canada, obtained his first Ph.D. degree in Mathematics from Kyoto University, Kyoto, Japan, in 1997, and another Ph.D. degree in Electrical Engineering from University of Delaware, Newark, USA. He was a post-doctor in the Department of Mathematics, Kyoto University from 1997 to 1998 and a Lecturer in the Ritsumeikan University and others in Japan from 1998 to 2002. From 2001, he moved to the Department of Electrical and Computer Engineering in University of Delaware as a visiting scholar and began his research on Multiple-Input, Multiple-Output (MIMO) systems and wireless communications theory and practice. He is an IEEE member. His research interests include wireless communications, multimedia communications, information theory, networking, mathematical applications to wireless communications, etc.