GPS接收机的失锁后处理研究

Research on Post Processing of Loss of Signal Lock in GPS Receiver

信号失锁是GPS接收机在市区应用时遇到的一个问题,文中提出信号失锁后的快速恢复概念,推导出在卫星信号失锁期间对其多普勒频率、码相位和导航比特边界的预测算法和预测误差分析,并进一步研究失锁后处理设计,最后用SPIRENT模拟源进行多种信号失锁情形的模拟,验证了此设计能增强接收机的稳健性,加快接收机失锁后的定位恢复速度。

GPS receivers frequently lose lock in urban environments.This paper introduces the fast recovery conception of GPS signal,deduces the prediction calculation formulas of Doppler frequency,code phase and navigation bit boundary during the period of losing GPS signal lock,and analyzes the prediction error.Then the post processing design of the loss of signal lock is studied,and several cases of losing signal lock are simulated by the SPIRENT GPS simulator.The simulation result proves that this design scheme can improve the receiver's robustness and the positioning recovery speed.