Carrier tracking loop design for high-dynamic BeiDou receivers

The conventional GNSS receiver is easy to lose lock in carrier-phase tracking loop under high-dynamic conditions, to improve tracking accuracy a new carrier tracking loop based on Adaptive Square-root Cubature Kalman filter (ASCKF) is proposed. Firstly, fine frequency estimation based on the phase measurement is used to provide precise initial value for the tracking loop. Secondly, the ASCKF-based carrier tracking loop depending on the structure of BeiDou2 navigation signal is designed. Finally, the adaptive factor according to the detection of carrier-to-noise ratio (CNR) and movement state is derived to adaptively calibrate the measurement noise covariance and the process noise covariance. The simulation results verify that the proposed algorithm could work well with the jerk up to 200g/s, and it has higher tracking accuracy compared with the algorithm based on adaptive extend Kalman filter.