基于部分相关和全相位预处理的伪码快速捕获方法

摘要

针对高动态长周期直接序列扩频信号的快速捕获问题,提出了利用部分相关和全相位预处理相结合的方法.对部分相关得到带有多普勒频偏的正弦信号进行全相位预处理,再经过FFT得到全相位幅值谱,检测到其累加平均后的最大值,就能得到较准确的多普勒频偏.通过理论分析和计算机仿真,该算法可以在很低的信噪比下完成伪码的捕获,同时能得到较精确的多普勒频偏值.%For the problem of long PN code capture in high dynamic Doppler shift situation in DSSS communications, this paper presented the method of using partial correlation and all-phase pre-processing to solve the problem. After using all-phase pre-processing and FFT to the sinusoidal signal that with Doppler shift, got the apFFT spectrum amphtude. By an average of the cumulative apFFT spectrum amplitude, it could get the more accurate Doppler shift. Theoretical analysis and computer simulation prove that the algorithm can capture the PN code in a low SNR, meanwhile, the algorithm can get the accurate Doppler shift.