关键词: 时延控制, 卫星导航系统, 多普勒补偿, 可变分数阶延迟滤波器

Abstract: Code Doppler should be compensated under high dynamic or weak signal conditions during Global Navigation Satellite Systems（GNSS） signal acquisition, which will lead to unacceptable acquisition gain loss. Code Doppler is compensated by delay control, including integer delay and fractional delay. Its implementation within GNSS signal acquisition based on integer delay lines and the variable fractional delay filter is proposed. The simulation results show that the new method has a perfect performance of compensating code Doppler, and detection loss can be reduced to less than 0.3 dB with a 4th-order fractional delay filter realized by FARROW structure.

Key words: delay control, Global Navigation Satellite Systems（GNSS）, Doppler compensation, variable fractional delay filter