MIMO-SCMA系统联合动态因子图检测

Joint dynamic factor graph detection for MIMO-SCMA system

针对MIMO-SCMA系统中联合消息传递算法(joint message passing algorithm,JMPA)复杂度较高的问题,对MIMO信道矩阵和SCMA码字的稀疏特性进行研究,提出一种基于置信度的动态因子图联合消息传递算法。在每一次迭代过程中利用置信度的稳定性信息,删除因子图中收敛速度较快的码字信息对应的传播分支,动态地确定下一次迭代所需的因子图,减少资源节点上用户更新数量。仿真结果表明,当资源节点选择合适的减少度数p时,所提算法的复杂度得到显著降低,能够与误码率取得良好的平衡。

Aiming at the high complexity of joint message passing algorithm(JMPA)in MIMO-SCMA system,the sparsity cha-racteristics of MIMO channel matrix and SCMA codeword were studied,a dynamic factor graph joint message passing algorithm based on confidence was presented.In each iteration process,the stability information of the confidence was used to deleted the propagation branch of codeword message with faster rate in factor graph,the factor graph for the next iteration was determined dynamically,the number of users updates on the resource node was reduced.The simulation results show that the complexity of the proposed algorithm is significantly reduced,and the bit error rate can be well balanced when the resource node selects the appropriate reduction degree p.