一种低复杂度的SCMA系统多用户检测算法

A Multi-user Detection Algorithm for SCMA System with Low Complexity

稀疏码多址接入(SCMA)作为一种新型非正交多址接入技术,可满足5G海量连接的性能需求,但其中消息传递算法存在收敛速度慢、复杂度高的问题。为此,针对SCMA系统提出一种低复杂度的多用户检测算法。通过减小译码时叠加码字星座点搜索范围并引入权重因子,改变搜索范围内叠加码字星座点的初始概率,从而加快译码速度并提高准确率。理论分析与仿真结果表明,该算法不仅能够有效降低复杂度,而且还能加快迭代过程的收敛速度。

As a novel Non-Orthogonal Multiple Access（NOMA） technology,Sparse Code Multiple Access（SCMA） can meet the performance requirements of massive connections for 5G,but the Message Passing Algorithm（MPA） has the problems of slow convergence and high complexity.In this paper,a multi-user detection algorithm for SCMA system with low complexity is proposed to slove above problems.By narrowing down the search range of superposed codeword constellation points and introducing the weighting factor,it changes the initial probability of superpoed codeword constellation points in the search range and makes the decoding process faster and more accurate.Theoretical analysis and simulation results show that the proposed algorithm not only reduces the complexity,but also accelerates the convergence speed of the iterative process.