高动态GPS载波跟踪算法和环路控制策略研究

Study on Algorithm and Control Strategies of GPS Carrier Tracking Loop Under High Dynamic Condition

在接收信号有较高的多普勒频率及其一阶、二阶导数存在的情况下仍能正常工作的接收机被称为高动态接收机。设计高动态接收机的关键是设计参数与结构合理的载波跟踪算法。本文针对高动态环境下载波跟踪所遇到的问题,重点研究了频率牵引算法,FLL辅助PLL复合环算法及重要参数的设计,并提出了一种新的分阶段载波跟踪控制策略。本文采用GPS模拟器产生的高动态信号为实验源,基于Matlab平台建立系统模型,仿真结果表明:采用文中提出的载波跟踪算法的GPS接收机能在加速度100g,加速度变化率40g/s的动态指标下正常工作。

High dynamic receivers refer to the receivers that can work normally under the high Doppler frequency,first-phase derivative and second-phase derivative environment.The keys to design high dynamic receivers are design parameters and a structurally reasonable carrier tracking algorithm.Aiming at carrier tracking problems in the high dynamic environment,the research focuses on the frequency traction algorithm,principle and parameter of FLL-assisted PLL loop,and the control strategies for a new phase-carrier tracking are put forward in this paper.The high dynamic signals from GPS simulator are used as the experimental source,and a system model is built based on Matlab platform.The simulation results show that the proposed GPS carrier tracking algorithm can work normally with the dynamic indexes of acceleration up to 100g and jerk up to 40g/s.