A Frequency-Compensation Algorithm in Kalman Filter-Based Tracking Loop for High-Dynamics GNSS Receivers

TL;DR: In this paper, a frequency compensation algorithm is proposed to make up the increasing phase error brought by signal's dynamics, and a mathematical analysis of the frequency-compensation method is given on how this method can help to form loop closure.

Abstract: GNSS receivers are expected to offer positioning service any time and any place. However, receivers with the traditional PLL/DLL tracking loops have limited performance under high-dynamics conditions because of the contradiction on bandwidth and update interval. This paper analyzes the influence on signal’s tracking algorithm caused by high dynamics, and then intend to improve tracking performance based on Kalman filter. The Kalman filter-based tracking scheme outperforms the traditional one in high-dynamics scenarios. In this paper the KF-based tracking loop is analyzed in depth and a frequency-compensation algorithm is proposed to make up the increasing phase error brought by signal’s dynamics. This paper will present a mathematical analysis of the frequency-compensation method. Moreover, a straightforward description is given on how this method can help to form loop closure. With the proposed algorithm, it is possible to use a longer pre-detection time as well as get a better dynamic performance. Simulation results have confirmed that it’s capable of the new designed KF-based loop to converge under high-dynamics scenarios with a Doppler rate over 2000Hz/s. And also the loop can obtain more accurate observations compared to the traditional tracking method.