非同步CDMA系统的低复杂度迭代多用户检测算法

Low-Complexity Iterative Multiuser Detection Algorithm for Asynchronous CDMA Systems

研究了基于非同步CDMA系统的低复杂度迭代多用户检测算法,给出了并行‘软’干扰消除随机数据联合(P-SC-PDA)和串行‘软’干扰消除随机数据联合(S-SC-PDA)两种算法,它们的计算复杂度均为o(K3)(K表示用户数).计算机仿真结果显示S-SC-PDA算法的性能明显优于P-SC-PDA算法.如果利用S-SC-PDA算法对被检测用户进行排序检测(根据译码器提供的信息先检测具有较高检测可靠度的用户,然后检测具有较低检测可靠度的用户),则系统的性能能进一步提高.

This paper presents two low-complexity iterative multiuser algorithms： parallel soft cancellation probabilistic data association （P-SC-PDA） and successive soft cancellation probabilistic data association （S-SC-PDA） for asynchronous CDMA systems. The computational complexity of the proposed algorithms is just 0 （ K^3 ） where K is the number of active users. Simulation results show that performance of the S-SC-PDA algorithm is significantly better than P-SC-PDA. With information delivered by the decoder, if the user signals to be detected is arranged such that signals of users with high detection reliabilities are detected first, and those with low detection reliabilities are detected later, even better performance can be obtained with S-SC-PDA.