在残余频偏下微弱直扩信号伪码周期的谱检测  

Method of spectra for periodic detection of the PN sequence in the weak DS-SS signals with residual carrier

作　　者：张天骐[1] 代少升[1] 杨柳飞[1] 李雪松[1] 

机构地区：[1]重庆邮电大学信号处理与片上系统研究所,重庆400065

出　　处：《系统工程与电子技术》2009年第4期777-781,共5页Systems Engineering and Electronics

基　　金：国家自然科学基金-中物院NSAF联合基金(10776040);国家自然科学基金(60602057);重庆市自然科学基金(2006BB2373);重庆市教委自然科学基金(KJ060509;KJ080507;KJ080517);教育部科学技术研究重点项目(207097);重庆市信号与信息处理重点实验室建设基金(2008NL0024)资助课题

摘　　要：针对存在残余频偏调制下的微弱直扩(DS)信号的伪码(PN码)周期截获的难题,拓展了先前提出的基于信号功率谱二次处理的方法。该方法先对带残余频偏调制的微弱DS信号求取功率谱,然后将所得到的功率谱作为一输入信号求取其第二次功率谱,于是所得二次功率谱将在PN码周期整数倍处出现代表信号存在的尖锐脉冲。通过对这些尖脉冲间的距离进行检测,就可以获得DS信号PN码周期参数的检测估计。理论分析和计算机仿真表明,该方法基本不受输入信号残余频偏的影响,在很大频偏和较低的输入信噪比条件下都能良好地工作。Aiming at the difficult problem o（ periodic detection and estimation of the pseudo noise （PN） sequence in the DS-SS signals with residual carrier, a novel detection method is developed. Firstly, the power spectrum of weak DS-SS signals with residual carrier is calculated, and then the second power spectrum is calculated once again by taking the first one as an input signal. Some regular tip-pulses appear at the integer times of period of the PN sequence while obtaining the second power spectrum. Thus, the period of PN sequence can be detected and estimated by measuring the interval of the regular tip-pules. The computer simu lation shows that the proposed method can work well on the lower signal to noise ratio input signals with larger residual carrier.

关 键 词：直接序列扩频(DS-SS)信号 伪码(PN)序列 功率谱二次处理 PN码周期截获 

分 类 号：TN911.5[电子电信—通信与信息系统]