多径环境下异步长码直接序列码分多址信号伪码序列及信息序列盲估计  

Blind Estimation of the Pseudo Noise Sequence and Information Sequence for Long Code Asynchronous DS-CDMA Signal in Multipath Environment

作　　者：周杨[1] 张天骐[1] ZHOU Yang;ZHANG Tianqi(Chongqing Key Laboratory of Signal and Information Processing,Chongqing University of Posts and Telecommunications,Chongqing 400065,China)

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：《电子与信息学报》2021年第4期1137-1144,共8页Journal of Electronics & Information Technology

基　　金：国家自然科学基金(61671095,61371164);信号与信息处理重庆市市级重点实验室建设项目(CSTC2009CA2003);重庆市杰出青年基金(CSTC2011jjjq40002)。

摘　　要：针对低信噪比(SNR)下存在多径效应的传统单通道异步长码直接序列码分多址(DS-CDMA)信号伪码序列(PN)及信息序列难估计问题,该文提出一种基于平行因子的多通道盲估计方法。该方法先将接收到的多径信号建模为多通道模型,然后将长码DS-CDMA信号建模成短码DS-CDMA信号的缺失数据模型,形成观测缺失数据矩阵,并将其等效为缺失平行因子模型,最后利用正则交替最小二乘法(ALS)对缺失平行因子进行低秩分解,实现多径环境下长码DS-CDMA信号各用户伪码序列及信息序列的盲估计。仿真结果表明,序列的估计性能与多径环境密切相关,且在莱斯因子为10,多径路数为3,通道数为4,用户数为6,信噪比大于–10 dB的条件下,伪码序列及信息序列的估计错误率均低于1%。For the problem of long code Direct Sequence-Code Division Multiple Access(DS-CDMA)signal in traditional asynchronous single-channel with multipath effect under low Signal-to-Noise Ratio(SNR),including blind estimation of the Pseudo-Noise(PN)sequence and information sequence,a method using multi-channel synchronous and asynchronous based on parallel factor is proposed.Firstly,the received signal in multipath environment is modeled as a multi-channel receiving model.And then the long code DS-CDMA signal is modeled as the short code DS-CDMA signal with missing data to form the observation missing-data matrix,which is equivalent to a parallel factor model with missing data.Finally,the regularized Alternating Least Squares(ALS)algorithm is applied to decompose the parallel factor,and the PN sequence and information sequence of long code DS-CDMA signals in multipath environment can be further estimated.Simulation results show that the performance of sequences estimation closely relates with the multipath environment,and the estimation error rate of 6 user PN sequences and information sequence is less than 1%under the condition that the Rician factor is equal to 10 and the number of path and channel are 3 and 4 respectively when the SNR is higher than-10 dB.

关 键 词：长码直接序列码分多址信号 缺失数据模型 多径环境 伪码序列 信息序列 

分 类 号：TN911.7[电子电信—通信与信息系统]