A Navigation-Data-Tolerated EKF Carrier Loop for GNSS Signals

Carrier loops using non-linear Kalman filters are effective for high-dynamic Global Navigation Satellite System (GNSS) tracking but are sensitive to data modulation and typically require navigation data (NavData) assistance. We propose a NavData-tolerant Extended Kalman Filter (NavEKF) carrier loop that accommodates data modulation and is applicable to various user dynamics, including high-dynamic scenarios. Simulation results indicate that the NavEKF outperforms the Kalman filter (KF)-based carrier loop with the Costas phase discriminator, enhancing tracking thresholds by 5 dB in high-dynamic and 1.5 dB in static conditions. Its independence from data aid broadens its application range compared to EKF.