Topic： Towards the Asymptotic Capacity of MIMO Cellular Two-Way Relay Networks

Time： 2015年5月22日（周五）上午10:00-11:00

Venue：信电大楼, 215学术会议室

Speaker：Xiaojun Yuan, Assistant Professor,

                  School of Information Science and

                  Technology，ShanghaiTech University

Biography

Xiaojun Yuan received the B.S. degree in Electronic and Information Systems from Shanghai Jiaotong University, the M.S. degree in Circuit and Systems from Fudan University, and the Ph.D. degree in Electrical Engineering from the City University of Hong Kong in 2008. From 2009 to 2011, he was a research fellow at the Department of Electronic Engineering, the City University of Hong Kong. He was also a visiting scholar at the Department of Electrical Engineering, the University of Hawaii at Manoa in spring and summer 2009, as well as in the same period of 2010. From 2011 to 2014, he was a research assistant professor with the Institute of Network Coding, The Chinese University of Hong Kong. He is now an assistant professor with the School of Information Science and Technology, ShanghaiTech University. His research interests cover a broad range of wireless communications, signal processing, and information theory including multiple-input multiple-output (MIMO) techniques, physical-layer network coding, cooperative communications, compressed sensing, etc. He has published over 70 peer-reviewed research papers in the leading international journals and conferences, and has served on a number of technical programs for international conferences. He was a recipient of the Best Paper Award of IEEE International Conference on Communications, Sydney, Australia, 2014.

Abstract

In this talk, we consider the transceiver and relay design for the multiple-input multiple-output (MIMO) cellular two-way relay channel (cTWRC), where a multi-antenna base station (BS) exchanges information with multiple multiantenna mobile stations via a multi-antenna relay station (RS). We propose a novel two-way relaying scheme to approach the sum capacity of the MIMO cTWRC. One of the key contributions of this work is a new nonlinear lattice-based precoding technique to precompensate the interstream interference, so as to achieve efficient interference-free lattice decoding at the relay. We derive sufficient conditions for the proposed scheme to asymptotically achieve the sum capacity of the MIMO cTWRC in the high signal-to-noise ratio (SNR) regime. To fully exploit the potential of the proposed scheme, we also investigate the optimal power allocation at the BS and the RS to maximize the weighted sum-rate of the MIMO cTWRC in the general SNR regime. We show that the problem can be formulated as a monotonic program, and a polyblock outer approximation algorithm is developed to find the globally optimal solution with guaranteed convergence. We demonstrate by numerical results that the proposed scheme significantly outperforms the existing schemes and closely approaches the sum capacity of the MIMO cTWRC in the high SNR regime.