Research On BDS Baseband Signal Tracking Algorithm And FPGA Implementation

Beidou navigation satellite system has been widely used in disaster prediction,communication services,road safety,geological survey and other fields since its establishment.As the signal coverage of Beidou navigation satellite system continues to expand,the research and development of its terminal equipment-satellite signal receiver has encountered unprecedented opportunities and challenges.Baseband signal processing module is an important part of satellite navigation signal receiver.The reliability of tracking module greatly affects the correct rate of demodulation of satellite navigation messages.The signal receiver can track the satellite navigation signal accurately and efficiently,which is the prerequisite for it to provide positioning,timing,communication and other services.Therefore,this thesisbaseband signal tracking algorithm research and implementation has important research significance.This thesis firstly introduces several basic aspects such as the positioning principle,the composition of signals,and the reasons for the reduction of positioning accuracy.Then,this paper introduces the acquisition and tracking algorithm in baseband signal processing in detail,and verifies the proposed algorithm by Matlab.Then,the article introduces the core content of this thesis-the FPGA design and implementation of the baseband signal tracking module.In Quartus Ⅱ development environment,this design uses hardware description language Verilog,adopts top-down design mode,and realizes baseband signal tracking module on FPGA.This design uses the Modelsim to verify the function of each module.After passing the verification,the board level test of the whole module is completed with Altera DE4 development platform.In this design,the navigation message demodulated by the tracking module is sent to the position solution module,and the final solution position is consistent with the real position within the allowable error range,proving the correctness of the hardware implementation of the tracking module.