基于分段相关-视频积累方法的伪码串行捕获优化设计  

Optimum Design of Serial PN Code Acquisition using Segment Correlation-Video Integration Method

作　　者：许晓勇[1] 唐小妹[1] 王飞雪[1] 

机构地区：[1]国防科技大学电子科学与工程学院卫星导航研发中心,湖南长沙410073

出　　处：《信号处理》2009年第9期1338-1341,共4页Journal of Signal Processing

基　　金：国防科技预研基金资助项目(106010304);新世纪优秀人才支持计划基金资助项目(NCET-04-0995)~~

摘　　要：本文主要针对载波多普勒下的伪码捕获问题,研究了基于分段相关-视频积累方法的伪码串行捕获系统的优化设计。通常的优化设计为假设峰值点的伪码相位偏差为0。但对于实际的捕获系统,由于接收到的伪码相位与本地伪码相位关系随机,在串行搜索过程中过门限值的伪码相位残差可能不为0,从而对捕获性能产生影响。本文主要分析伪码相位偏移残差对峰值点的信噪比和检测概率的影响,并给出了最大伪码相位偏移残差下的平均捕获时间表达式。同时基于平均捕获时间最小准则,给出了搜索步进推荐值。对虚警概率指定和未指定两种情况分别进行了优化设计,得到了最优的中频积累和视频积累设计值,该设计值与载噪比、多普勒容限等因素相关。研究成果可用于指导扩频接收机伪码捕获模块的设计。A serial PN code acquisition system using segment correlation-video integration method is optimized to deal with carrier Doppler. Usually the optimized method supposes that the peak value corresponding to the residual code phase offset is zero. In fact in a chip-asynchronous system the residual code pahse offset is not zero when the corr-value is over threshold, which willl effect the performance of the acquisition. In the article below, the residual code phase offset problem is disclosed when the system is chip-asynchronous. Signal to noise ratio and detection probability is studied when residual code phase offset exits. And the mean acquisition time （MAT） formula was obtained under maximum residual code phase offset. Based on minimum-MAT criterion, preferable search step size is suggested. Also optimum design is investigated under false probability given or not. Under each mode, IF integration and video integration values are calculated,which values vary with carrier to noise ratio and Doppler tolerance. The results can be used in code acquisition module of spread spectrum system receiver.

关 键 词：扩频 伪码捕获 串行捕获 中频积累 视频积累 

分 类 号：TN914.42[电子电信—通信与信息系统]