Research on high dynamic signal acquisition algorithm of low Earth orbit satellite

In the future, space-based measurement and control of LEO satellites will be an effective means to improve the management and control ability of massive satellites. Aiming at the problem of fast signal acquisition caused by fast satellite motion speed, large Doppler frequency and short visual time when receiving space-based signals, this paper studied the applicability of PMF-FFT (partial match filter-fast Fourier transform) high dynamic acquisition algorithm to the system, and analyzed the determinants of acquisition Doppler range, the requirements of acquisition for signal-to-noise ratio and the related factors of average acquisition time, and these were verified by Matlab simulation.

The results showed that when the Doppler was 95 kHz, the SNR (signal noise ratio) was more than -25 dB, and the average acquisition time was less than 200 ms. For different signal systems and Doppler frequencies, the length of matched filter and the number of FFT points need to be adjusted. The acquisition algorithm was suitable for LEO satellite on-board terminals.