部分相关与功率谱相结合的伪码快捕算法  

Rush Capture of PN Code Based on Method of Partial Correlation and Power Spectrum

作　　者：刘燕丽[1] 张天骐[1] 苗圃[1] 高清山[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

出　　处：《测控技术》2009年第11期14-18,31,共6页Measurement & Control Technology

基　　金：国家自然科学基金-中物院NSAF联合基金项目(10776040);国家自然科学基金项目(60602057);信号与信息处理重庆市市级重点实验室建设项目(CSTC;2009CA2003);重庆市科委自然科学基金项目(CSTC;2006BB2373);重庆市教委自然科学基金项目(KJ060509;KJ080517)

摘　　要：针对极微弱动态长周期伪码直接序列扩频信号的捕获问题,提出了利用部分相关和功率谱相结合的方法,进行伪码相位延时/多普勒频偏的快速二维并行搜索。通过部分相关,得到反映多普勒频偏的正弦信号,在低信噪比下,通过功率谱累积平均达到检测微弱信号的目的。该捕获方法在捕获到同步长周期伪码的同时,也得到了多普勒频偏值的近似值。给出了基于该算法的信号模型、捕获方案及性能分析,并在此基础上分析了FFT点数、加窗函数及累积次数对捕获性能的影响。在理论分析的前提下,通过计算机仿真验证了该方法有良好的捕获效果。For the problem of long PN code capture in DS-SS communications, the method which combines with partial correlation and cumulative power spectrum is presented. Through partial correlation, a sinusoidal signal is got, which reflects the Doppler shift. By an average of the cumulative power spectrum, the purpose of weak signal detection at low signal to noise ratio is achieved. Using this method, the synchronized PN code phase and approximation value of Doppler shift are got. At the same time, the signal model, the capture scheme and performance analysis arc given. Based on this, the impact of FPF points, adding window function and the cumulative power spectrum to the capture performance are analyzed. In the end, the computer simulation proves that this method has favorable capture performance.

关 键 词：部分相关 周期图 功率谱 捕获性能 

分 类 号：TP391.9[自动化与计算机技术—计算机应用技术]