基于最小二乘的同步多用户非周期长码直扩信号扩频序列估计  

Estimation of the spread spectrum sequence for synchronous multi-user aperiodic long-code DSSS signals based on least squares

作　　者：张天骐[1] 强幸子 马宝泽 王俊霞[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：《电波科学学报》2016年第6期1113-1123,共11页Chinese Journal of Radio Science

基　　金：国家自然科学基金(61671095;61371164;61275099);信号与信息处理重庆市市级重点实验室建设项目(CSTC2009CA2003);重庆市教育委员会科研项目(KJ130524;KJ1600427;KJ1600429)

摘　　要：针对低信噪比下同步多用户非周期长码直扩信号的扩频序列估计问题,提出了一种基于嵌套迭代最小二乘投影算法的扩频序列估计方法.首先,将同步多用户非周期长码直扩信号等效为含有缺失数据的相应的短码直扩信号.然后,利用最大似然估计理论对相应的短码直扩信号进行数学分析,构建扩频序列估计的数学模型.最后,利用一种嵌套迭代最小二乘投影算法来实现扩频序列的估计.研究表明,该算法在低信噪比(小于-10dB)情况下,对多用户(多达10路)扩频序列的估计有着良好的性能表现.This paper studies the problem of estimation of the spread-spectrum sequence for low SNR synchronous multi-user long-code direct sequence spread spectrum（DSSS）signals.An estimation approach of spread-spectrum sequence based on a nested iterative least squares with projection（NILSP）algorithm is presented.First,The synchronous multi-user long-code DSSS signals is constructed as the shortcode ones with missing data.Then the mathematical analysis for the short-code ones with missing data is done based on the theory of maximum likelihood estimation（MLE）to establish a mathematical model of spread-spectrum sequence.After that,the spread-spectrum sequence is estimated by a NILSP algorithm.The theoretical analysis and simulations show that,the proposed algorithm always has a good performance for estimation of multi-users＇（more than 10 users）spread-spectrum sequence in low-SNR（lower than-10 dB）scenarios,and under the same conditions,the longer the data size,the better the performance.

关 键 词：长码直扩信号 缺失数据模型 最大似然估计 嵌套迭代最小二乘投影算法 

分 类 号：TN911[电子电信—通信与信息系统]