Design And Realization Of Positioning Solution Algorithms In BeiDou Navigation Receiver

With the development of the BeiDou navigation system, its application fields are expanding widely, meanwhile the demand of the BDS receiver is also increasing. The structure and emphasis of receiver in different application scenarios are different, but the positioning module is always the key part. This paper focuses on the design and development of the overall structure and positioning module of the BDS receiver.Firstly, we in brief introduce the elementary knowledge of BDS, including the composition of BDS, the structure of the BDS signal and the positioning principle of the receiver. Then, we have studied the least square algorithm and the Extended Kalman Filter(EKF) method in the pseudorange positioning. The performance of these two methods in static and dynamic scene has been measured. According to the analysis of advantages and disadvantages of these two methods, we have designed an improved EKF algorithm that combing the following measures: using the least square solution as initial value, adding the procedure of filter divergence detection, improving recursive model and other means. Such that, the algorithm would be more stable and efficient.Secondly, we have designed the whole structure for the receiver based on the Xilinx Zynq platform. We used the processing logic and processing system of Zynq efficiently by the AXI bus and configurable IP core. The software/hardware processing of receiver can be simplified, which provides a better verification platform for the BDS signal design.Finally, we have implemented the positioning solution module in the BDS receiver. The overall control process of the receiver has been developed. The positioning software module includes the navigation message decoding analysis, satellite solution, pseudorange calculation and correction, position/velocity/time solution, dilution of precision calculation and forecasting ephemeris solutions. We have also developed the data display software of the receiver. At last, the performance of the overall receiver has achieved comparable results, especially due to the improvement of positioning solution module.