Acquisition technique for navigation signals based on pre-average process

To resolve large resource consumption and low Doppler resolution problem of traditional acquisition algorithm, a fast acquisition method based on pre-average and coefficient variable matched filter is proposed. The method stores the received intermediate-frequency signals and pseudo-code into corresponding dual-ports memory, completes correlation through coefficient variable matched filter, analyses the spectrum of correlation result by FFT. Finally, the maximum value of FFT output is verified to finish the Doppler estimation and acquisition process. The proposed method saves 50% hardware resources while reaching the same integration time, and can improve the Doppler resolution which can improve the probability of signal tracking. The experiment results show that this method can implement modern multi-frequency GNSS signals acquisition through the flexible configuration.