Partial intersection sphere decoding with weighted voting for sparse rotated V-OFDM systems  

作　　者：Qi FENG Xiang-Gen XIA Naitong ZHANG 

机构地区：[1]School of Electronic Science and Engineering,Nanjing University,Nanjing 210023,China [2]College of Information Engineering,Shenzhen University,Shenzhen 518060,China [3]Department of Electrical and Computer Engiineering,University of Delaware,Newark DE 19716,USA [4]School of Electronics and Information Engineering,Harbin Institute of Technology,Harbin 150001,China

出　　处：《Science China(Information Sciences)》2018年第2期73-85,共13页中国科学（信息科学）（英文版）

基　　金：supported by National Natural Science Foundation of China(Grant No.61401194);China Scholarship Council(Grant No.201406190083);Program B for Outstanding Ph.D.Candidate of Nanjing University(Grant No.201501B013)

摘　　要：Vector orthogonal frequency division multiplexing（V-OFDM） is a general system that builds a bridge between OFDM and single-carrier frequency domain equalization in terms of intersymbol interference level and receiver complexity. In this paper, we focus on a rotated V-OFDM system over a broadband sparse channel owing to its large time delay spread and fewer nonzero taps. In order to collect the multipath diversity,a simple rotation matrix is designed, independent of the number of subchannels at the transmitter. For the rotated V-OFDM receiver, a partial intersection sphere decoding with weighted voting method is proposed by exploiting the sparse nature of the multipath channel. The proposed receiver chooses the transmitted vector from the set with the maximum likelihood estimation generated using the partial intersection sphere decoding method. For an extreme case, such as when a candidate set is empty, which usually occurs at a low signal-to-noise ratio（SNR）, an efficient weighted voting system is used to estimate the transmitted vectors symbol-by-symbol. Simulation results indicate that the proposed receiver improves the symbol error rate performance with reduced complexity, especially for low SNR scenarios.Vector orthogonal frequency division multiplexing（V-OFDM） is a general system that builds a bridge between OFDM and single-carrier frequency domain equalization in terms of intersymbol interference level and receiver complexity. In this paper, we focus on a rotated V-OFDM system over a broadband sparse channel owing to its large time delay spread and fewer nonzero taps. In order to collect the multipath diversity,a simple rotation matrix is designed, independent of the number of subchannels at the transmitter. For the rotated V-OFDM receiver, a partial intersection sphere decoding with weighted voting method is proposed by exploiting the sparse nature of the multipath channel. The proposed receiver chooses the transmitted vector from the set with the maximum likelihood estimation generated using the partial intersection sphere decoding method. For an extreme case, such as when a candidate set is empty, which usually occurs at a low signal-to-noise ratio（SNR）, an efficient weighted voting system is used to estimate the transmitted vectors symbol-by-symbol. Simulation results indicate that the proposed receiver improves the symbol error rate performance with reduced complexity, especially for low SNR scenarios.

关 键 词：vector orthogonal frequency division multiplexing sparse multipath channel partial intersection sphere decoding weighted voting diversity order 

分 类 号：TN929.53[电子电信—通信与信息系统]