基于自调整器的CDMA系统盲自适应干扰抑制

Blind Adaptive Interference Suppression for CDMA Systems Based on Self-Tuning Regulator

本文给出一种能同时抑制DS CDMA系统多址干扰 (MAI)和窄带干扰 (NBI)的盲自适应算法 .此方法基于遗忘因子具有自调整器的迭代最小二乘算法 (SR RLS) ,根据系统的变化自动调整遗忘因子 ,当系统趋于静态时 ,遗忘因子趋于 1,以提高稳态精度 ,在动态系统中 ,遗忘因子减小 ,使算法能有效的跟踪系统参数 .与其它的迭代最小二乘相比 ,具有较小的稳态误差和良好的动态跟踪能力 .文章从理论上分析了算法的收敛性 .最后 ,对算法在静态环境和动态环境中的性能分别进行了仿真分析 .

This paper develops a blind adaptive interference suppression algorithm for simultaneously suppressing multiple-access interference (MAI) and narrow-band interference (NBI) in direct sequence code division multiple-access (DS-CDMA) systems.This method is based on RLS with a self-tuning regulator for the forgetting factor(SR-RLS).When the system becomes stationary,the forgetting factor approaches to unit for a small steady-state error,while the system is dynamical,then the forgetting factor decreases to make the novel algorithm possess the ability to track dynamical parameters.Compared with other RLS algorithms,it has smaller steady-state error and better ability of tracking dynamical parameters.The convergence of the algorithm is theoretically analyzed.Lastly through simulation the performances of the algorithm under the stationary and dynamical environments are investigated respectively.