Performance analysis of typical Kalman filter based GPS tracking loop

The tracking loop is an important part of GPS receiver, and its performance has great influence upon the receiver. So the tracking performance of tracking loop is underlined in this paper. To improve the performance of traditional tracking loop, three typical structures of Kalman filter based tracking loops are investigated, which are carrier and code combined Kalman filtering loop, carrier and code separated Kalman filtering loop and carrier only Kalman filtering loop. The performances of these three typical tracking loop structures are compared and analyzed in tracking and navigation domains, respectively. The results show that the performances of these three Kalman filter based tracking loop are better than the traditional non Kalman filter based tracking loop, especially in signal weak environment, and the performance of the carrier and code separated Kalman filtering loop is the best in the three typical Kalman filter based tracking loops. Furthermore with the decreasing of carrier-to-noise ratio, the advantage of Kalman filter becomes greater.