Research On High Dynamic BDS Satellite Signal Acquisition

BDS is China’s self-developed navigation and positioning system, which provides users with all-weather, real-time navigation and positioning capabilities and communications services. The system has a very broad application prospect, especially in the military, which provides high-precision navigation and positioning capabilities for artillery shells, missiles and other high-speed movement weapons. Since the fast satellite signals acquisition is the key to achieve high dynamic navigation, it is very important to study fast acquisition algorithm in high dynamic environment.Firstly, this thesis introduces the development of BDS and the fast acquisition technology at home and abroad. Secondly, this thesis introduces the structure and signal characteristics of BDS. Thirdly, this thesis analyzes the acquisition principle. Then it analyzes the time domain serial acquisition algorithm, FFT-based parallel acquisition algorithm and combination of matched filter and FFT-based acquisition algorithm and compares the advantage and disadvantage of these methods.Based on the analysis of traditional acquisition method, this thesis proposes an improved fast acquisition method in high dynamic. This method analyzes the principle of integrated navigation and combines WSN (wireless sensor network), INS (inertial navigation system) and PMFB (partial matched filter band)-FFT (Fast Fourier Transform). This method makes best use of the advantages of each device and makes up their shortcomings. The WSN information is used to enhance the ability to acquire the weak signal and reduce the search range. The Doppler information provided by the INS is used to reduce the Doppler search range. The PMFB-FFT algorithm is used to search the C/A code phase and carrier frequency in parallel. This method can reduce the acquisition time. Finally, simulation results verify the effectiveness of the algorithm.