Mitigation of GNSS Time Synchronization Attacks in a Multicorrelator Receiver

Global navigation satellite systems (GNSSs) are widely used in various fields to provide high-precision timing. However, their low signal power and open signal structure render GNSS receivers vulnerable to time synchronization attacks (TSAs). In this study, we propose a novel single-antenna-based TSA mitigation algorithm. First, a multicorrelator estimator was adopted to calculate the parameters of the authentic and counterfeit signals. Then, the predicted pseudorange was derived for spoofing validation, and the counterfeit signals were subtracted. Finally, a robust extended Kalman filter was adopted to resist gross errors in the estimation results. A series of Monte Carlo simulations were conducted to evaluate the performance of the proposed method with different relative delays and power advantages of the spoofing signals. The Texas Spoofing Test Battery spoofing datasets were used in the experiments to verify the effectiveness of the proposed algorithm. The results indicated that the timing errors decreased from
$2.0~\mu \text{s}$
(600 m) to 53.4 ns (16 m), and the spoofing signals were considerably mitigated. The proposed anti-spoofing algorithm can ensure the availability of GNSS timing under TSAs and only requires a single antenna, greatly simplifying the GNSS receiver installation and reducing costs.