卫星定位处于高动态的GPS接收系统中,信号正确捕获是系统的关键技术.系统的高动态特性,使GPS信号产生相位延迟和多普勒频移,加大了信号捕获的难度.研究相关器的工作原理,并且分析了目前已有捕获方法的特点和不足,提出了一种能够重复利用FFT变换结果半数谱线的快速捕获的方法,进一步对载波多普勒频移进行了精确估计,以满足跟踪通道的需要.原理上证明了改进方法的可行性,通过仿真表明,改进算法可实现信号的准确快速捕获.%In the system of high dynamic GPS receiver in the satellite positioning, the key technology of the system is signal acquisition. The high dynamic characteristics of the system make GPS signal phase delay and doppler frequency shift, which increases the difficulty of signal capture. In this paper, the correlator theory was studied, and the characteristics and shortcomings of the present capture methods were analyzed. A fast acquisition method which can reuse the FFT results was presented, and the doppler frequency shift of the carrier wave was accurately estimated , to meet the needs of the track channels. This method is proved feasibly in theory. The simulation shows that the algorithm can realize the quick capture of signals.
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