基于加权消息传递的SCMA多用户检测算法

Multiuser signal detection method for SCMA systems based on weighted message passing

针对稀疏码多址接入(sparse code multiple access,SCMA)技术中,消息传递算法(message passing algorithm,MPA)收敛速度较慢导致复杂度较高的问题,提出一种基于加权消息传递的SCMA多用户信号检测改进算法。在原始MPA的基础上,通过引入权重因子改变每个叠加星座点的初始概率,使靠近接收信号的星座点可以获得更大的初始概率,加快迭代过程的收敛速度。仿真结果表明,与原始MPA算法相比,改进算法在误比特率(bit error rate,BER)和复杂度之间达到了较理想的平衡。

Aiming at the slow convergence rate of message passing algorithm(MPA)leading to higher complexity in sparse code multiple access(SCMA)system,a SCMA multiuser signal detection method based on weighted message passing was proposed.Weighted factors were introduced to change the initial probability of each superposed constellation points,and therefore the constellation points closed to the received signal might obtain larger initial probabilities which made the convergence rate of the iterative process better.The simulation results show that the proposed scheme can obtain good trade-off between complexity and bit error rate(BER)performance compared with the original MPA algorithm.