一种基于串行更新的分组门限MPA算法

A Threshold Grouped Message Passing Algorithm Based on Serial Updating Strategy

针对上行SCMA系统通常采用消息传递算法(Message Passing Algorithm,MPA)进行多用户检测,但其存在复杂度高、收敛速度慢等问题,造成较长的系统时延,故提出一种基于串行更新的分组门限MPA检测算法,为不同分组中的用户设置判决门限及不同的最小迭代次数,减少串行更新过程中所需更新用户节点的个数.理论和仿真结果表明,该算法可在保证误比特率(Bit Error Rate,BER)性能的情况下有效降低译码复杂度,减小系统时延.

The uplink SCMA system generally employs the message passing algorithm（MPA） for multi-user detection. However,there are some problems such as high complexity and slow convergence rate which lead to long time delay. In the report,a threshold grouped MPA detection algorithm was proposed,based on a serial message update strategy. Threshold and different minimum number of iterations were set for users in different groups. The number of user nodes to be updated in the serial updating process can be appropriately reduced in the proposed scheme. The results of theoretical analyses and simulation showed that the proposed algorithm can effectively reduce the decoding complexity and the latency of the system while maintaining good BER performance.