Research On Acquisition Algorithm Of Beidou Navigation Receiver B1 Signal And Implementation Based-on FPGA

In recent years, satellite navigation industry gets rapid development, and represented by America’s global positioning system(GPS), global navigation satellite system(GNSS) is playing an increasingly import role in people’s daily life and work. With the using of our country’s BeiDou satellite navigation system, which is independently constructed and operated, the research on BeiDou navigation receiver is of great significance to the development of our country’s satellite navigation industry, and also gradually becomes the hot point of research. Acquisition is an important link in the navigation receiver and cons of acquisition algorithm determines the navigation receiver’s performance. In this thesis, BeiDou satellite signal acquisition algorithm is researched, designed and verified.Firstly, the principle of satellite navigation and characteristics of BeiDou satellite B1 signal are introduced in this thesis. In this part, ranging codes generation method is introduced in detail, and the autocorrelation features of the ranging codes are analyzed, which is ready for acquisition algorithm research. Then the structure of navigation receiver is introduced, which shows that acquisition plays an important role in navigation receiver. And then the basic acquisition principle of BeiDou B1 signal is analyzed, and three kinds of basic acquisition algorithm are discussed:serial acquisition algorithm, frequency domain parallel acquisition algorithm and time domain parallel acquisition algorithm. In the end, computation of the three algorithms is analyzed in comparison.Secondly, the influence of bit transition and its position of navigation message to the acquisition result is analyzed in this thesis. In the view of the bit transition of navigation message, a kind of mimic circular correlation algorithm is proposed, and combined with the FFT operation, an modified time-domain parallel acquisition algorithm is put forward. In the view of the navigation message of BeiDou D2 signal, merge strategy is designed, and MATLAB simulation of the MTPA is analyzed. Then combining with the peak detection methods and Monte Carlo simulation, the performance of the acquisition algorithm is analyzed. In the end, the solution to the weak signal is proposed.Finally, the modified time-domain parallel acquisition algorithm for FPGA verification is performed in this thesis. In order to save resources during hardware implementation, the average sampling module is joined, and it also reduces the amount of calculation. The design principle and flow chart of each module are introduced in detail in this thesis. Implement, simulation and verification of each module are developed under the ISE software using Verilog HDL language. Finally, the whole module is verified, and the results of the verification show that the design can acquire the BeiDou satellite signals very well.The acquisition algorithm in this thesis which has been designed and verified aims at BeiDou satellite signal, solves the effect of the navigation message bit transition, and it uses the parallel acquisition algorithm, which greatly improves the speed of acquisition. So, this acquisition algorithm is of valuable for the development and application of BeiDou satellite navigation system in China.