Research On High Gain Coding Method Of GNSS Based On Polar Codes

As an important means of obtaining positioning,speed and time,the global satellite navigation system is of great significance to the country's military,economy and people's daily life.In order to ensure the accuracy and reliability of the navigation service and reduce the noise and interference during the transmission of the navigation signal,channel coding plays an important role in it.As an emerging coding method,Polar code has been proved to be able to reach the Shannon limit theoretically for the first time,and with the in-depth study of its theory,the performance of Polar code is also constantly improving.Based on the research and simulation of existing navigation signal coding methods,this paper explores and verifies the feasibility of applying Polar codes to satellite navigation systems by studying the construction,coding and decoding methods of Polar codes.In this paper,the structure and coding method of GPS L1 C signal and QZSS L6 signal in current navigation system are studied and simulated.According to the construction method of Polar code under additive white Gaussian noise channel,the Bhattacharyya parameter method and Gaussian approximation method are studied,and the optimal design signal-to-noise ratio points under two construction modes are found by simulation.Then the different decoding algorithms of Polar code are studied in depth.The problems of SC decoding algorithm,BP decoding algorithm and SCL decoding algorithm are analyzed,and the performance simulation of CA-SCL decoding algorithm is compared.Finally,the performance of the code modulation scheme based on Polar code and the scheme of GPS L1 C signal and QZSS L6 signal is presented.The results show that the channel coding scheme based on Polar code has obvious performance improvement over the existing scheme,which provides a useful reference for GNSS channel coding design.