Acquisition Technology for the Third Beidou Satellite Navigation Signal with Low Signal-to-Noise Ratio and High Dynamic

In order to solve the problem of acquisition of the third generation Beidou satellite navigation signal with low SNR and high dynamic, a BOC (1,1) signal acquisition technology based on the non-coherent accumulation of BPSK-like PMF-FFT is proposed. The influence of carrier Doppler frequency offset and code Doppler on PN code acquisition is considered simultaneously in this algorithm, according to searching range for Doppler frequency offset, first-order Doppler frequency offset changing rate and code Doppler, the parameters of acquisition algorithm are determined, and the quantitative analysis results of detection value are given. The detection probability formula of the acquisition algorithm is derived, and its correctness is proved, Compared with the minimum carrier to noise ratio of Beidou system, the algorithm in this paper has a margin of 9.7db in the worst case. Finally, the scheme of carrier Doppler rate of change and code Doppler compensation for extremely low SNR and high dynamic signals is given.