GPS接收机C/A码跟踪算法及环路控制策略

The Algorithm and Control Strategy of GPS C/A Code Tracking Loop

高动态GPS接收机指在接收信号有较大的多普勒频率偏移及其一阶、二阶导数存在时仍能正常工作的GPS接收机。针对高动态环境下伪码跟踪所遇到的问题,重点研究了与高动态载波跟踪算法相匹配的、基于载波辅助技术的归一化非相干点积功率伪码跟踪算法,以及预检积分时间可变的伪码跟踪环路控制策略。采用MATLAB建立了系统模型,仿真结果表明:采用伪码跟踪算法以及结合相应的高动态载波跟踪算法的伪码跟踪控制策略的GPS接收机能在加速度为80 g,加速度为10 g.s-1的指标下正常工作。

High dynamic receivers refer to the receivers that can function properly under the circumstance with large Doppler frequency shifting,first-phase derivative and second-phase derivative.This paper focuses on problems that come from C/A code tracking under high dynamic circumstance.In accordance with the algorithm of high dynamic C/A code tracking and based on carrier tracking techniques,the major study covers the algorithm of C/A code tracking that features normalized incoherent dot-product power and the control strategies of the C/A code tracking loop that features changeable pre-integral time.The systematic mode is built on MATLAB.The simulation results show that GPS receivers can function properly under the condition of an acceleration of 80g and a jerk of 10g/s through the algorithm of C/A code tracking and the control strategy of high dynamic code tracking.