An EKF Based Tracking Loop Filter Algorithm in GNSS Receiver for Ultra High Dynamic Environment: The Experiment Results

Abstract

The Global Navigation Satellite System (GNSS for short) is original constructed to perform navigation and control tasks as an open, compatible, global, and independent navigation system. To achieve success operating, we have to overcome numerous challenges, chief among which are the need for avoiding the contradiction between the loop bandwidth and tracking accuracy in traditional linear tracking loop and obtain stability and performance (such as positioning accuracy) in the high dynamic case. Although appealing from the utilization perspective, several limitations still restrict their practical applications, especially in the high dynamics scenarios. To mitigate the aliasing artifacts caused by the traditional linear tracking loop and obtain high performance, it proposed in the current paper an improved Extended Kalman Filter (EKF for short) based signal tracking algorithm, where the phase detector, frequency detector and tracking loop filter in traditional tracking loop are replaced by EKF modules. The ultra high dynamic EKF carrier model and measuring model are utilized to perform the design and analysis procedures. This paper carried out comparison numerical simulations and experiments on the BMN2200S GNSS receiver platform using the proposed EKF carrier method against the traditional linear tracking loop mechanism. The results yielded in the hardware experiment showed that much better results are observed, in terms of much fast convergence speed of signal tracking and stability performance, especially for high dynamic case. It seems that the current technique provides an insight in how to tune the receiver and improve the GNSS's ability in performing navigation and control tasks, and also paves a potential way for both theoretical and engineering applications.