一种多址移动通信系统异步Schwarz串行干扰消除算法

An Asynchronous Schwarz-SIC Algorithm of Multiple Communication System

针对多址通信系统中的串行干扰消除(SIC)多用户检测算法检测过程因用户功率排序错误导致判决误差扩散进而算法检测精度下降、收敛性不足及移动通信系统整体性能下降的问题,结合Schwarz算法对强多址干扰和码间干扰情况下直接序列扩频码分多址(DS-CDMA)系统中的SIC算法进行了研究,提出了一种Schwarz-SIC多用户检测算法(S-SIC)。新算法通过Schwarz约束条件实现对各用户功率子域边值的精确控制,减少用户排序出错,可全面跟踪时变信道,且在干扰消除检测过程中有效避免判决误差的扩散,抑制MAI及ISI的影响。在误码性能、收敛性,动态跟踪能力及算法精度方面较原有SIC算法有较大提高。仿真结果验证了新算法是一种有效的多址通信系统干扰消除算法。

The detection precision of Successive Interference Cancellation （SIC） detector is always affected by the diffusion of decision error. A Schwarz-SIC multi-user detection algorithm was proposed combined with Schwarz algorithm for the Direct Sequence Spread Spectrum Code Division Multiple Access （CDMA） system with strong multiple access interference （MAI） and intersymbol interference （ISI）. The S-SIC algorithm achieved precise con- trol of the power sub-domain boundary value on each user~ by Schwarz constraints, then reduced the user sort er- ror. This new algorithm can full track the time-varying channel, solve the problem of decision error diffusion in the decision process of single SIC algorithm and achieve the purpose of MAI and ISI. Simulation results show that the new algorithm has better convergence, dynamic tracking ability and algorithm precision.