摘要： 在稀疏码多址接入(SCMA)系统的多用户检测过程中,MAX-Log消息传递算法(MPA)由于采用了近似计算造成部分消息丢失,检测性能较差。为此,通过理论推导得出更接近真实值的约近方法,提出一种改进的MAX-Log MPA算法。对资源节点消息更新公式乘以一个值为2的常数,从而减少原始MAX-Log MPA因近似计算造成的消息丢失,提升MAX-Log MPA多用户检测器的检测性能。理论与仿真结果表明,改进算法能够在保持原算法低复杂度优点的同时,有效提升检测性能。

关键词: 稀疏码多址接入, 多用户检测, 消息传递算法, 并行, 串行

Abstract: In the multi-user detection processes of Sparse Code Multiple Access(SCMA) system,MAX-Log Message Passing Algorithm (MPA) causes partial loss of messages due to the approximate calculation,which makes its detection performance poor.Aiming at the above problem,an improved MAX-Log MPA algorithm is proposed in this paper by introducing an approximate method closing to the true value.In this algorithm,the resource node message update formula multiplies with a constant 2,which can effectively reduce the message loss caused by the approximate calculation of the original MAX-Log MPA,thereby improving the detection performance of the MAX-Log MPA multi-user detector.Theoretical and simulation results show that the improved algorithm can not only maintain the low complexity of the original algorithm,but also obtain better detection performance.

Key words: Sparse Code Multiple Access(SCMA), multi-user detection, Message Passing Algorithm(MPA), parallel;serial

中图分类号: 

• TN929.5