Generalized message passing detection of SCMA systems based on dynamic factor graph for better and flexible performance-complexity tradeoff  

作　　者：Fangqi DONG Huijuan ZHENG Lei MA Sheng TONG 

机构地区：[1]State Key Laboratory of Integrated Services Networks,Xidian University,Xi’an 710071,China [2]School of Electronic Engineering,Xi’an University of Posts and Telecommunications,Xi’an 710061,China

出　　处：《Science China(Information Sciences)》2022年第5期238-245,共8页中国科学（信息科学）（英文版）

基　　金：supported by National Natural Science Foundation of China(Grant Nos.61871029,61771364);Fundamental Research Funds for the Central Universities(Grant No.JB190122.)。

摘　　要：Multiuser detection based on the message passing algorithm(MPA)has been considered for sparse code multiple access(SCMA)systems.Recently,some complexity-reduced MPA detectors have been proposed,among which the MPA detector based on dynamic factor graph(DFG-MPA)has been shown to outperform other MPA detectors with comparable complexities.However,all these MPA detectors are somehow not very flexible in terms of performance-complexity tradeoff,i.e.,the granularities of computational complexity reduction are relatively large.In this paper,a generalized scheme of DFG-MPA,termed as GDFG-MPA,is proposed to make a better and more flexible performance-complexity tradeoff.The proposed scheme features two aspects:(1)instead of banning a message update forever,a banned message update at some iteration is allowed to be updated at later iterations;(2)different numbers of message updates are banned from updating at different iterations.Optimization of GDFG-MPA can be made by allocating banned message updates among iterations.Numerical results have demonstrated that compared to DFG-MPA the proposed GDFG-MPA can achieve much better performance at the same computational complexity or achieve the same performance with much lower complexity.Moreover,the proposed GDFG-MPA is more flexible in tuning the performance and complexity tradeoff.

关 键 词：sparse code multiple access(SCMA) multiuser detection message passing algorithm(MPA) factor graph computational complexity 

分 类 号：TN929.5[电子电信—通信与信息系统]