基于变量节点串行策略的SCMA低复杂度译码研究

摘要

Sparse code multiple access technology,as a competitive non orthogonal multiple access scheme for the fifth generation wireless communication network,has a broad application prospect.However,current SCMA uplink use the flooding scheme of message passing algorithm for decoding,both the detection complexity and convergence properties are not ideal.A serial message passing algorithm which changed the information updating strategy was proposed,which performed message processing and deliveried according to the order of the variable nodes.Each of variable node simultaneously performed the reception of the verification message and the transmission of the variable message.The theoretical and simulation results show that the proposed algorithm not only maintains good performance,but also has low decoding complexity.%稀疏码多址接入(SCMA)技术作为5G无线通信网络的一个竞争性的非正交多址方案,具有广阔的应用前景.但目前基于SCMA的上行链路均采用泛洪方案的消息传递算法(MPA)进行译码,无论是检测的复杂度还是收敛速度都不甚理想.提出一种改变信息更新策略的串行消息传递算法——S-MPA (serial MPA),按照变量节点的次序进行消息处理和传递,每一个变量节点同时进行校验消息的接收和变量消息的发送.理论和仿真结果表明,该算法不仅能保持良好的性能,而且也有较低的解码复杂度.