Research On Simulation Of Beidou Satellite Navigation System

Based on theoretical research of satellite navigation,the Beidou satellite navigation system simulation platform presented in this paper restore entire operation process of the Beidou satellite navigation system.Focusing on the development of the Beidou satellite navigation system simulation platform,the architecture of the system,the generation of the Beidou signal,and the acquisition and tracking of the Beidou signal are studied in this paper.This paper gives an analysis of composition of the Beidou satellite navigation system,a design of simulation platform of Beidou satellite navigation system based on the space segment,ground segment,user segment and Beidou signal transmission environment of Beidou satellite navigation system.The software and hardware environment of the simulation platform are explained,and the application process of the simulation platform introduced.Aim at the QPSK signal modulation mode used by the current stage of the Beidou satellite navigation system,this paper conducts analyses and simulations on new system signals,such as BOC signal and MBOC signal and Alt BOC signal,which will be used in the next phase of the Beidou system,and uses the simulated power spectrum for analysis and study.This paper realizes the Beidou signal acquisition and tracking by CUDA programming and achieves the signal acquire through the parallel code phase search and acquisition method which gives the Doppler frequency and code phase offset.Then,the signal is tracked using the acquired results in the way that constructs tracking loops with Costas carrier tracking loop and Early-Late code phase tracking loop.Finally,This paper brings about the implementation of the Beidou satellite navigation system simulation platform,including the monitoring station module,ground station module,uplink channel module,satellite module,downlink channel module and receiver module.The simulation platform includes the generation method of the navigation signal,the capture method of the navigation signal and the tracking method of the navigation signal,and can realize the modeling and simulation of the Beidou satellite navigation system at the signal level.The monitoring station is for operational management of the overall system;the ground station injects modulated navigation signal into the upstream channel through which the signal is injected into the satellite;the satellite demodulates the navigation message and injects it into the downlink channel modulation;the downlink channel injects navigation information into the navigation receiver;the receiver demodulates the navigation message from the downlink channel after the signal can be captured and tracked,and finally positioning results are resolved.