DFT-Spread MIMO Systems: Iterative Equalization, Evolution Analysis, and Precoder Optimization

Speaker: Prof. Xiaojun Yuan (CUHK)

Time and Date: 10:30-11:30, Jul. 1, 2013

Place: Room B415, Building of Computing Centre, Handan Campus

Abstract

We develop a novel belief-propagation (BP) based iterative equalization algorithm for discrete-Fourier-transform (DFT) spread multiple-input multiple-output (MIMO) systems. An evolution technique, referred to as signal-to-interference-plus-noise-ratio (SINR) variance transfer chart, is established to accurately characterize the behavior of the proposed equalizer. We show that the proposed scheme significantly outperforms the existing non-linear MIMO equalizers in various system setups. We further investigate the precoder design based on the newly developed evolution technique, under the assumption of both full and partial channel state information at the transmitter (CSIT). We derive the optimal precoding directions, and show that the precoder optimization then boils down to a simple power allocation problem that is solvable using convex programming. Numerical results demonstrate that the optimized precoder can achieve a significant power gain, as compared with the non-optimized scheme.

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 City University of Hong Kong in 2008. After graduation, he was a research fellow at the Department of Electronic Engineering, City University of Hong Kong. During 2009-2010, he was also working as a visiting scholar at the University of Hawaii at Manoa. He is now a research assistant professor at the Institute of Network Coding, Department of Information Engineering, The Chinese University of Hong Kong. His research interest falls into the general area of signal processing and information theory, including channel coding and coded modulation, massive multiple-input multiple-output (MIMO) communications, physical-layer network coding (PNC), etc. He has published over 40 refereed papers in the leading journals and conferences in the related areas. He served as the Technical Program Committee (TPC) members for several international conferences including ICC, WCNC, PIMRC, etc.