A Two-stage Fast Pseudo-code Acquisition Algorithm Based on PMF-FFT
Bai Zhongyuan, Bo Li, Cui Wen · 2020
Aiming at the problems of slower speed and higher resource occupation of traditional navigation satellite signal acquisition algorithms under low signal-to-noise ratio and high dynamic environment, a two-stage acquisition algorithm combining coarse and fineness is proposed. This algorithm uses a two-stage PMF-FFT (Partial Match Filter-Fast Fourier Transform) capture unit as the basic model. The first-stage partially matched filter searches for 64 chip phases each time, and then performs FFT operation to limit the ambiguity of the code phase to a small range of chips; In the second stage, based on the previously obtained small-range chips, the signal data slides forward one chip at a time relative to the local C/A code sequence, which effectively avoids traversing many invalid frequency points. Improve the computational efficiency, thereby speeding up the capture speed. Experimental results show that the algorithm can achieve good capture performance during the capture process, and has broad application prospects.