基于平淡卡尔曼滤波的微弱GPS信号跟踪算法

The Algorithm for GPS Weak Signal Tracking Using Unscented Kalman Filter

在接收信号很微弱的情况下,全球定位系统(GPS)的传统方法不能很好地跟踪信号.采用非线性卡尔曼滤波算法取代传统的延迟锁定环和相位锁定环,用于高灵敏度GPS接收机的微弱信号处理环节.针对所提出的微弱信号系统模型中相关运算的特点,运用平淡卡尔曼滤波器进行信号跟踪.仿真结果表明,新方法能够较好地跟踪到载噪比低至27 dB-Hz的微弱信号,确保了跟踪精度;同时具有较高的灵敏度.

This paper presented a new tracking method which uses nonlinear Kalman filter instead of the traditional methods including delay locked loop and phase locked loop, to address the problems of weak signal processing for high-sensitivity GPS receivers. Process model and measurement model were proposed to track the GPS weak signals. According to the characteristics of signal correlation, unscented Kalman filter was used to investigate the models. The simulation results show that the weak signal with noise ratio as low as 27 dB-Hz can be well tracked by the proposed method. And it can ensure both high precision and high sensitivity.