A LOW-COMPLEXITY ITERATIVE RECEIVER FOR MULTIUSER SPACE-TIME BLOCK CODING SYSTEMS

作     者：HA H. NGUYEN YAJUN YANG 

作者机构：Department of Electrical & Computer Engineering University of Saskatchewan Saskatoon Canada S7N5A9 Canada 

出 版 物：《International Journal on Wireless & Optical Communications》 

年 卷 期：2007年第4卷第2期

页      面：143-164页

学科分类：0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 

主　　题：Multiuser system space-time coding interference cancellation joint detection and decoding sigma mapping EXIT chart 

摘      要：In an iterative receiver of a bandwidth-efficient multiuser space-time block coding (STBC) system, the extrinsic information is iteratively exchanged among the soft-input soft-output (SISO) channel decoders, the soft-output multiuser detector and the soft-output M-ary demodulators. Error performance, complexity and efficiency of the extrinsic information exchange are the most important properties of an iterative receiver. Taking these factors into account, sigma mapping is first applied to M-QAM constellations to yield a low-complexity soft-output minimum mean squared error (MMSE) demodulator to be used in the iterative receiver. Then a low-complexity two-loop iterative receiver is proposed for the multiuser STBC systems. It is shown that by running an additional inner iteration (between the channel decoders and the M-ary demodulators) for every outer iteration (between the channel decoders and the multiuser detector), the proposed receiver is superior to the conventional one, in which only one inner iteration is executed per one outer iteration. The results in this paper are therefore useful for wireless applications that employ space-time coding and require a very high bandwidth efficiency.