Improve the Security of GNSS Receivers Through Spoofing Mitigation

Spoofing attacks are one of the most dangerous threats for the application of the global navigation satellite system (GNSS), especially for autonomous driving and unmanned aerial vehicles. In this paper, we present a more robust spoofing mitigation algorithm based on subspace projection that is independent of the number of antennas and that can be utilized in single-antenna GNSS receivers. During a spoofing attack, authentic signals are contaminated by spoofing signals. We demonstrate that all spoofing signals can be eliminated by projecting the received signal onto the orthogonal null space of the spoofing signals. Moreover, two types of receiver structures are designed: a centralized structure that has the ability to suppress cross-correlation interference and a distributed structure with lower computational complexity and lower projection power losses. The proposed algorithm is verified by the Beidou B1I signals for improving the security of the receiver.