下行MIMO-SCMA链路中的快速多用户检测算法  

Fast Multiuser Detection Algorithm in Downlink MIMO-SCMA Link

作　　者：张徐芳 张钧鑫 李卓航 习彤 姜军 ZHANG Xufang;ZHANG Junxin;Li Zhuohang;XI Tong;JIANG Jun(College ofInformation Science and Technology,Tibet University,Lhasa Tibet,850000;Information Technology National Experimental Teaching Demonstration Center of Tibet University,Lhasa Tibet,850000)

机构地区：[1]西藏大学信息科学技术学院,西藏拉萨850000 [2]西藏大学信息技术国家级实验教学示范中心,西藏拉萨850000

出　　处：《通信与信息技术》2023年第5期19-24,共6页Communication & Information Technology

基　　金：国家自然科学基金资助项目(项目编号:62261051);西藏大学珠峰学科建设计划项目(项目编号:zf22002001)。

摘　　要：随着物联网、智慧终端等新技术的发展,目前的无线通信系统已经无法适应人们关于海量接入、低时延、高速率通信的需求。稀疏码多址接入(Sparse Code Multiple Access,SCMA)作为一种码域非正交多址接入技术,可以在有限的频率资源上提供更多的接入,而MIMO(Multiple-Input Multiple-Output)技术通过多天线提高了系统容量,因此MIMO-SCMA系统可以进一步增加接入数量、提高通信速率。通过对MIMO-SCMA系统下行链路中两种传统的级联式算法,即基于迫零(ZF)、最小均方误差(MMSE)均衡的消息传递(MPA)算法进行原理推导,研究了下行链路中的联合消息传递算法(Joint Message Passing Algorithm,JMPA),通过用户、多天线和信道资源块构建虚拟的联合因子图,通过仿真实验,验证了JMPA算法BER性能比传统的级联式算法更好且具有较好的收敛性。With the rapid development of new information technology,such as Internet of things and intelligent terminal,the current wireless communication systems cannot meet the requirements of mass connection,low delay and high-speed communication.As a Code-domain non-orthogonal Multiple Access(SCMA)technology,Sparse Code Multiple Access(SCMA)can provide more connections on limited frequency resources,and MIMO(Multiple-Input Multiple-Output)technology can improve system capacity by Multiple antennas,therefore,MIMO-SCMA can further increase the number of connections and improve the communication rate.In this paper,the principle of two traditional concatenated algorithms in the downlink of MIMO-SCMA system,namely the message passing(MPA)algorithm based on zero-forcing(ZF)and minimum mean square error(MMSE)equalization,is derived.The Joint Message Passing Algorithm(JMPA)in the downlink is studied.A virtual joint factor graph is constructed by users,multiple antennas and channel resource blocks.Through simulation experiments,it is verified that the BER performance of the JMPA algorithm is better than the traditional concatenated algorithm and has better convergence.

关 键 词：稀疏码多址接入 下行链路 消息传递 

分 类 号：TN929.5[电子电信—通信与信息系统]