资源块间跳频的高可靠SCMA系统设计与分析  

Design and Analysis of a Reliable SCMA System Based on Inter-RBs Frequency Hopping

作　　者：曾琦[1,2] 杨坤 方科[2] 郝黎宏[2] 牛宪华[3] 钟俊 刘星[1] ZENG Qi;YANG Kun;FANG Ke;HAO Lihong;NIU Xianhua;ZHONG Jun;LIU Xing(College of Electrical Engineering,Sichuan University,Chengdu 610040,China;Southwest China Institute of Electronic Technology,Chengdu 610036,China;School of Computer and Software Engineering,Xihua University,Chengdu 610039,China)

机构地区：[1]四川大学电气工程学院,成都610040 [2]中国西南电子技术研究所,成都610036 [3]西华大学计算机与软件工程学院,成都610039

出　　处：《电讯技术》2024年第7期1123-1131,共9页Telecommunication Engineering

基　　金：四川省重点实验室开放式基金资助项目(2023-0529-04-02);四川省科技计划资助项目(2023NSFSC0480);抗干扰国家重点实验室开放基金项目(2022-JCJQ-LB-079)。

摘　　要：传统稀疏码分多址(Sparse Code Division Multiple Access,SCMA)系统在固定时频资源块(Resource Block,RB)上传输信息,系统性能易受到信道污染(外在干扰和信道衰落)的影响。为了解决这一问题,提出一种基于资源块间跳频(Frequency Hopping,FH)的SCMA系统(FH-SCMA系统)。借助跳频技术实现动态SCMA码字复用,使得各用户能够均匀、随机地使用所有资源块。同时,基于素数序列设计了一种动态码字正交复用的跳频策略(跳频码),提升了FH-SCMA系统容量以及抗干扰能力。该系统接收端采用对数域消息传递(MAX-log-MPA)多用户检测算法,推导了该FH-SCMA系统的理论误码率上界。对比传统的SCMA系统,该资源块间FH-SCMA系统能均匀化资源块被污染对用户性能的影响,使得每个用户的传输误码率达到可接受的程度;相比传统SCMA系统和采用完全随机跳频策略的FH-SCMA系统(干扰时频资源占比η=25%时),设计的跳频策略及FH-SCMA系统在误码平层处分别获得4 dB和8 dB的信噪比增益。The prototypical sparse code division multiple access(SCMA)system always transmits the non-zero code-words over the fixed resource blocks(RBs),thus likely suffering from severe performance degradation due to the contaminated RBs(jamming attacks or channel fading).For this problem,an improved SCMA system based on inter-RBs hopping is proposed.With the help of the frequency hopping(FH)technology,dynamic code word multiplexing is realized,which enables users to use all RBs uniformly and randomly.To implement the optimal inter-RBs FH-SCMA,a pseudo-random hopping strategy is designed via prime code and interleave ring operations.To reduce the complexity,a logarithmic domain messaging multi-user detection algorithm(MAX-log-MPA)is used at the receiver.The theoretical up-bound of bit error rate of the proposed FH-SCMA system is derived.Compared with the traditional SCMA system,the proposed system can average the effect of contaminated RBs on BER performance,and obtain signal-to-noise ratio gains of 4 dB and 8 dB at the error-floor under the ratio of jammed time-frequency resourcesη=25%.

关 键 词：SCMA系统 资源块跳变 高可靠传输 抗干扰设计 

分 类 号：TN929.5[电子电信—通信与信息系统]