MC-DS-CDMA信号的伪码周期盲估计  

Blind estimation of PN sequence's period for MC-DS-CDMA signal

作　　者：钱文瑞[1] 张天骐[1] 周杨[1] 闫振华[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：《计算机工程与设计》2016年第4期862-866,876,共6页Computer Engineering and Design

基　　金：国家自然科学基金项目(61371164;61275099;61102131);信号与信息处理重庆市市级重点实验室建设基金项目(CSTC2009CA2003);重庆市杰出青年基金项目(CSTC2011jjjq40002);重庆市自然科学基金项目(CSTC2012JJA40008);重庆市教育委员会科研基金项目(KJ120525;KJ130524);重庆市研究生科研创新基金项目(CYS14140)

摘　　要：为解决多载波直扩码分多址(MC-DS-CDMA)信号伪码周期估计的问题,提出基于二次谱的伪码周期估计算法。利用MC-DS-CDMA信号子载波间和不同用户扩频码间的正交性特点,在接收端对该信号求一次功率谱,将得到的功率谱作为输入信号求傅氏变换并取模平方,搜索二次谱上的脉冲尖峰并检测间距,得到MC-DS-CDMA信号的伪码周期。理论推导MC-DS-CDMA信号二次谱表达式,对比二次谱法与二阶矩法的计算复杂度。仿真结果表明,该算法可有效估计MCDS-CDMA信号的伪码周期,适用于低信噪比环境。To solve the pseudo-noise（PN）sequence＇period estimation problem in multicarrier direct sequence spread spectrum code division multiple access（MC-DS-CDMA）signals,the method based on reprocessing the power spectrum was proposed.Using orthogonality characteristics among different carriers and that among different users＇ PN sequences,apower spectrum of the received signal was computed and treated as an input signal to compute its second power spectrum density,and the value was squared.Through detecting the interval of the peak pulses,the period of PN sequence of MC-DS-CDMA signals was obtained.The MC-DS-CDMA signal＇s secondary spectrum expression was derived with theory,and computational complexity was compared with the second-order moment method.Results of simulation show that the algorithm can estimate the cycle of PN sequence efficiently,and it works well under the condition of low signal-to-noise ratio.

关 键 词：多载波直扩码分多址 功率谱 伪码周期 正交频分复用 信噪比 

分 类 号：TN911.7[电子电信—通信与信息系统]