多用户大规模LDPC-SM-MIMO联合分层消息传递检测  

Joint Layered Message Passing Detection for Multi-user Large-scale LDPC-SM-MIMO System

作　　者：邹鑫 张顺外[1] ZOU Xin;ZHANG Shunwai(College of Telecommunications and Information Engineering,Nanjing University of Posts and Telecommunications,Nanjing 210003,China)

机构地区：[1]南京邮电大学通信与信息工程学院,南京210003

出　　处：《计算机科学》2023年第11期327-332,共6页Computer Science

基　　金：江苏省高等学校自然科学研究项目(20KJB510034);南京邮电大学宽带无线通信与传感网技术教育部重点实验室开放研究基金(JZNY202112);南京邮电大学国自基金孵化项目(NY219073)。

摘　　要：对于多用户大规模空间调制多输入多输出(Spatial Modulation Multiple Input Multiple Output,SM-MIMO)系统,消息传递检测(Message Passing Detection,MPD)是常用的检测算法,但其复杂度较高。针对该问题,引入基于分层消息传递机制的分层MPD(Layered MPD,LMPD)算法以加快算法收敛速度,降低算法复杂度。进一步,将低密度奇偶校验码(Low-density Parity-check,LDPC)与SM-MIMO系统相结合,提出联合LMPD-BP(Joint LMPD Belief Propagation,JLMPD-BP)算法,LMPD算法可利用BP算法反馈的概率信息,提升系统检测性能。理论分析与仿真结果表明:与传统MPD算法相比,LMPD算法在不损失误码率性能的前提下可加快算法收敛速度,当信噪比(Signal-to-Noise Ratio,SNR)为4 dB时,MPD算法需3次迭代才能达到收敛,而LMPD算法仅需2次迭代即可收敛;同时,通过与LDPC码结合,JLMPD-BP算法极大地降低了系统误码率,如在迭代次数为(2,2,2)、SNR=2 dB时,与迭代次数为(4,4,0)的LMPD-BP算法相比,JLMPD-BP算法的误码率由10-2降至5×10-3。Message passing detection(MPD)is the most commonly used detection algorithm in multi-user large-scale spatial mo-dulation multi-input multi-output(SM-MIMO)systems,but the traditional MPD algorithm is still complex.To overcome this pro-blem,the layered MPD(LMPD)algorithm isused to accelerate the convergence speed of the algorithm.Then,low-density parity-check(LDPC)codes are combined with SM-MIMO systems,and a joint LMPD-belief propagation(JLMPD-BP)algorithm in which the LMPD can use the feedback information of BP decoding is proposed to further improve the system detection perfor-mance.Theoretical analysis and simulation results show that,compared with the traditional MPD algorithm,the LMPD algorithm accelerates the convergence speed of the algorithm without losing the bit error rate(BER)performance.For example,when the signal-to-noise ratio is 4 dB,LMPD algorithm need only 2 iterations,while MPD algorithm need 3 iterations.At the same time,thanks to the great advantages of LDPC codes,JLMPD-BP algorithm greatly reduces BER of the system.When the iteration number is(2,2,2)and SNR=2 dB,compared with LMPD-BP algorithm with iteration(4,4,0),the BER of JLMPD-BP algorithm deceases from 10-2 to 5×10-3.

关 键 词：分层消息传递检测 空间调制 大规模MIMO LDPC码 置信度传播 

分 类 号：TN929.5[电子电信—通信与信息系统]