无线光码分多址中一种改进的盲多用户检测算法  

A Modified Blind Multi-User Detection Algorithm for Wireless Optical Code Division Multiple Access Systems

作　　者：吴鹏飞[1] 柯熙政[1] 梁薇[1] 

机构地区：[1]西安理工大学自动化与信息工程学院,陕西西安710048

出　　处：《光学学报》2012年第2期79-84,共6页Acta Optica Sinica

基　　金：国家自然科学基金(60977054)资助课题

摘　　要：干扰消除是无线光码分多址(CDMA)通信系统中的一项关键技术。分析了基于递归最小二乘(RLS)算法的盲多用户检测算法的原理及性能,并将其应用于采用光正交码的无线光CDMA系统中。讨论了该系统中遗忘因子的选取原则及其对算法的收敛性和系统误码率性能的影响。为了克服固定遗忘因子所带来的矛盾,提出了一种改进的变遗忘因子RLS盲多用户检测算法,并对遗忘因子进行了修正。结果表明,采用改进的方法后系统能获得较快的收敛速度和跟踪速度,收敛时的估计误差也较小,而且信号干扰比由传统算法的6dB提高到9dB。说明采用变遗忘因子的RLS算法不仅适合于采用光正交码的无线光CDMA系统,而且跟踪期望用户信号的性能良好。Interference cancellation is one of the key technologies in wireless optical code division multiple access（CDMA） systems.The principle and performance of blind multi-user detector algorithm based on recursive least square（RLS） are analyzed,and it is applied to wireless optical CDMA using optical orthogonal code（OOC）.The selecting principle of forgetting factor,the convergence and error rate performance caused by forgetting factor are discussed.A RLS blind multi-user detection algorithm is proposed using variable forgetting factor.The forgetting factor is modified.The results show that the system using the improved method can get faster convergence speed and tracking speed of convergence and the estimation error is smaller.The signal to interference ratio is improved from 6 dB of the traditional algorithm to 9 dB.The RLS algorithm with variable forgetting factor is suitable for the wireless optical CDMA system using OOCs,and the performance of tracking the desired user signal is very good.

关 键 词：光通信 无线光码分多址 盲多用户检测 递归最小二乘 

分 类 号：TN929.1[电子电信—通信与信息系统]