Research and Implementation on Long Code Rapid Direct Acquisition Technique of GNSS Receiver

For the long-code rapid direct acquisition algorithm in Global Navigation Satellite System(GNSS),the circular correlation method based on Fast Fourier Transform(FFT) and Multi-bank matched filter + FFT method are mainly studied in terms of principle and framework.Applying array antenna technique in GNSS receiver improves the performance of long code direct acquisition under low SNR.At last,the two methods are well implemented on the same hardware platform in engineering,and the experimental data are analyzed and compared.The results of experiment indicate that each of the two methods has its own advantages and disadvantages,and can rapidly implement long code direct acquisition under low SNR and high dynamics,which is very meaningful to rapid positioning and navigation of GNSS receiver.