多速率DS/CDMA信号扩频序列并行盲估计方法  

Parallel Blind Estimation of Spreading Sequences in Multi-rate DS / CDMA Signals

作　　者：吴旺军[1] 张天骐[1] 石穗 张亚娟[1] 

机构地区：[1]重庆邮电大学信号与信息处理重庆市重点实验室,重庆400065

出　　处：《信息与控制》2015年第2期171-178,共8页Information and Control

基　　金：国家自然科学基金资助项目(61371164;61071196;61102131);重庆市市级重点实验室建设项目(CSTC2009CA2003);重庆市杰出青年基金资助项目(CSTC2011jjjq40002);重庆市自然科学基金资助项目(CSTC2012JJA4008);重庆市教育委员会科研资助项目(KJ20525;KJ130524)

摘　　要：针对可变扩频长度多速率直接序列码分多址(direct sequence/code division multiple access,DS/CDMA)信号扩频序列盲估计问题,提出了一种基于盲源分离的并行估计方法,该方法首先利用二次功率谱的方法估计出信号不同速率的扩频码周期,然后利用多速率DS/CDMA信号周期特性将信号依据周期并行地建模为主用户和干扰用户(即将同一周期下的用户视为主用户,其余的用户和噪声一律视为独立的单个干扰用户)的模型,最后针对同步和异步两种情况,分别以单倍周期和两倍周期长度对数据进行分割,生成数据矩阵,并结合稳健的矩阵联合近似对角化(JADE)算法对扩频序列进行并行的盲估计.计算机仿真结果表明方法在较低信噪比下有效.To solve the problem of blind estimation of spreading sequences for the variable spreading length multi-rate DS/CDMA signals,a new parallel blind estimation algorithm,based on blind source separation,is pro-posed.Firstly,the method uses the reprocessing of the power spectrum algorithm to estimate the periods users employ different rates of spreading sequences.Secondly,based on period characteristics,the signals are mod-eled with primary users and interference users,treating users with the same period as primary users and others as interference users.Finally,for synchronous and asynchronous systems,the signals are divided into single or double times of spreading period length,respectively,forming a data matrix.The robust JADE algorithm is used for the blind estimation of the spreading sequences.The computer simulation results show that this meth-od performs well at lower signal-to-noise ratios.

关 键 词：多速率DS/CDMA(direct sequence/code DIVISION multiple access DS/CDMA) 扩频序列 并行估计 二次功率谱 矩阵联合近似对角化(JADE)算法 

分 类 号：TN911[电子电信—通信与信息系统]