大动态直扩信号的快速捕获方法
Fast Acquisition Method for High Dynamic DSSS Signal
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摘要: 针对大动态环境下直接序列扩频信号的快速捕获问题,提出了一种两轮频域搜索的捕获方法. 该方法采用快速傅里叶变换实现伪码的并行相关,通过两轮频域搜索完成捕获. 第1轮搜索整个多普勒频率范围,得到各个频点的峰均比,选大后进行门限判决;第2轮搜索进行多普勒频率的小范围验证. 分析和仿真结果均表明,对于直接序列扩频信号的快速捕获,提出的方法具有更高的捕获精度、更好的捕获性能,尤其适用于大多普勒频率及其变化率的动态环境.Abstract: In view of the acquisition problem for high dynamic direct sequence spread signals, a new method of acquisition is presented. The method completes signal acquisition by twice frequency domain search based on fast Fourier transform. In this method, the whole range of Doppler frequency for signals is searched in addition with a second round verification. Analysis and simulation results indicate that the principle of the method is correct and it has better acquisition accuracy and great performance especially for higher dynamic environment.
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