Design And Implementation Of Beidou B1I Satellite Navigation Signal Simulator

In recent years,the Beidou navigation satellite system has been widely used,and the surging demand for navigation and positioning services has promoted the development of Beidou receiving terminal technology.As the vital equipment in the development and testing of receiving terminals,Beidou satellite navigation signal simulator’s function of customized navigation signal design provides a test environment with plentiful scenes for receiving terminals.Therefore,it is of great significance to develop the Beidou satellite navigation signal simulator.Firstly,the dissertation analyzes and collates the domestic and foreign research status of satellite navigation signal simulator,and systematically summarizes the Beidou B1 I signal structure,details the carrier signal,ranging code and the navigation message specific parameters and the corresponding specification of the Beidou navigation coordinate and time system.Then,starting from the working principle of the navigation receiving terminal,determine and model the key parameters in the simulator signal.After analyzing the principle of navigation signal simulation and sorting out the traditional algorithm,a navigation signal simulation algorithm based on phase reset and Doppler interpolation is proposed.Its performance is validated by computer simulation,the results show that the algorithm has the characteristics of low implementation difficulty and high precision.In the aspect of algorithm implementation,according to the proposed navigation signal simulation algorithm,a signal generation method capable of delay any phase based on ZYNQ is designed.The detailed implementation method is given from four levels of signal carrier,ranging code,navigation message and NH code,and then elaborate the navigation signal modulation and SNR configuration principle.In whole system test,it is confirmed that this method can generate the Beidou B1 I satellite navigation signal can with excellent real-time and accuracy performanceThe hardware platform adopts a "host computer+ZYNQ+AD9361" hardware architecture.The host computer enables the user to interact with the simulator to monitor its working status and design the signal.ZYNQ is the main carrier of signal generation.The RF front-end uses the AD9361 module to realize the up-conversion and digital-to-analog conversion of digital IF signal,and broadcasts the Beidou B1 I satellite navigation signal through the antenna.In order to ensure the smoothness and efficiency of the interaction between PS and PL,a data interaction path based on OCM and shared interruption is designed,and shows its whole interaction process.Finally,the function and performance of the Beidou B1 I satellite navigation signal simulator developed in this subject are tested.The results show that the simulator can broadcast the customized B1 I satellite navigation signal with a maximum of 8 channels.The positioning error of the terminal is less than 5m and the timing accuracy is up to 26 ns.The proposed signal simulation algorithm and generation method are highly fit,which smoothly transitions from algorithm and theory to engineering implementation,and has good performance in the designed hardware architecture of simulator.It has a promising application prospect,and provides certain reference value and guiding significance for the research and development of the Beidou satellite navigation signal simulator.