Design and capability analyze of GNSS high dynamic carrier tracking loop based on UKF

The carrier tracking loop of global navigation satellites system (GNSS) receiver in high dynamic conditions was researched, and an open-loop carrier tracking method based on unscented Kalman filter (UKF) was proposed. This new method adopts the four-dimensionality UKF phase estimator to increase the tracking accuracy, and compensates the estimated values to reduce the hysteresis of the filter. Besides, it can eliminate the harmful affect of BPSK modulation on the UKF. The performance of this open loop was compared with the closed loop in the aspects of tracking errors, unlocking probability and bit error rate (BER) by simulating the received signal of GPS in high dynamic movement, and the results show that this open-loop compensation method can remarkably improve the tracking precision (decreasing the tracking errors by 50%), the convergence of UKF (leading to lower probability loss of lock), and the BER performance (improved by 1.5 dB).