Research And Implementation Of Key Technology For Signal Processing Of Beidou Satellite Navigation Receiver

With the development of Beidou system and service capabilities,the application of Beidou related products is more and more extensive.Therefore,the research of receivers,especially baseband signal processing algorithms,has become the key to navigation applications.After studying the format and characteristics of the Beidou signal,the core technology capture and tracking of the receiver is mainly studied.The research contents are as follows:First,a detailed study on the acquisition algorithm of Beidou signal is carried out.Firstly,the time domain serial acquisition algorithm,parallel frequency and parallel code phase acquisition algorithm are studied.The FFT acquisition algorithm is simulated by matlab,and the performance results,acquisition time and computational performance of the algorithm are given.An improved acquisition algorithm is studied.The algorithm combines the partial matched filter with the FFT to superimpose the local pseudo code of one chip locally by 64 points and perform PMF capture with the 64-point superimposed signal.The PMF-FFT algorithm is verified by the actual IF data collected by the satellite navigation experimental platform.The results show that the algorithm can reduce the computational complexity and improve the acquisition speed.Then,the Beidou signal tracking algorithm was deeply studied.The carrier tracking loop and code tracking loop are studied.The research and verification of the Costas loop and the frequency-locked loop are carried out.The code loop delay locked loop is designed and verified.The results show that the designed tracking algorithm can effectively track the synchronization to the navigation signal.Finally,the hardware implementation of the design acquisition algorithm is realized by FPGA,and the design of digital down conversion module,carrier NCO module and local ranging code NCO module is realized.Through the embedded logic analyzer embedded in the Quartus II software,the signals of each module are captured in real time,and the function verification is performed.The result shows that the designed capture module can effectively capture the Beidou navigation signal.