基于FFT/iFFT的GPS信号捕获算法研究

Research on Acquisition Algorithm of GPS Signal Based on FFT/iFFT

利用快速傅立叶变换和反变换(FFT/iFFT)在频域实现循环相关是一种GPS C/A码快速捕获的有效方法,其可以将时频二维的联合滑动相关搜索转化为一维频域搜索,实现了伪码的并行搜索,可以有效地缩短GPS信号的捕获时间。同时,针对弱信号捕获提出了相关和非相干累积的方法,并给出了试验结果。

Making use of FFT/iFFT to realize circular correlation in frequency domain is an effective method for GPS C/A code rapid acquisition. It can help translate 2D Time-frequency joint sliding correlation searching into 1D frequency domain searching, and realize parallel searching for pseudo-code, which can shorten the acquisition time of GPS signal. Meanwhile, the cumulative methods of coherent integration and non-coherent integration which according to the weak signal acquisition are presented, and the test results are given.