Research On Acquisition Algorithm Of Satellite Signal Modulated By High Order BOC And Implementation On FPGA

Recently,satellite navigation system has entered the high-speed development period.It has been an important development strategy to deploy the satellite navigation system all over the world.Time service and location service offered by Global Navigation Satellite System are applied to each field.To complete and develop the satellite navigation system,it is necessary to make a deeply research on navigation receiver.Acquisition module is a core technology of navigation receiver,determining the receiver's performance.Binary offset carrier（BOC）modulation is applied to new generation receiver widely.BOC modulation has not only outstanding advantages,such as high precision and quality of anti-multipath,but also problems like ambiguous acquisition.This thesis focuses on the acquisition of high order BOC modulation and FPGA implementation.First of all,the theory of satellite navigation and a deep research on signal modulated by BOC are introduced in this thesis.Secondly,the structure of navigation receiver is introduced.Acquisition is an three-dimensional searching process.According to the theory of acquisition,traditional acquisition algorithm is compared by simulation and analysis.Coherent integration and incoherent integration are analyzed in weak signal environment.Next,Bump-jump,autocorrelation function reconstruction,BPSK-like are simulated and compared in performance.Aiming at the signal modulated by high order BOC,a time parallel acquisition with multi-peak detection（TPAMPD）algorithm is designed,simulated and analyzed.The simulation results show that the algorithm can capture the signal with carrier to noise ratio of40dB·Hz unambiguously.The capture probability is more than 0.9 when the false alarm probability is less than 10^-3.Finally,the acquisition algorithm is implemented on FPGA.Acquisition modules is designed and simulated by Verilog HDL,and verified on Xilinx VC707,proving the feasibility.Time parallel acquisition with multi-peak detection algorithm can meet the needs of navigation receiver and acquisition modules implemented on FPGA can capture the high order BOC modulated signals.The design can be transplanted to the System on Chips（SOC）with high performance and practicability.