GNSS Receiver Anti-Spoofing via PRN Replica Shape Anomaly
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Solution Overview
Problem
Current GNSS receivers are vulnerable to spoofing attacks, which can lead to incorrect position estimation and decision-making, especially in autonomous and assisted driving applications, and existing solutions require additional hardware or specific constellation tracking.
Innovation Solution
A method that involves generating multiple replicas of the Pseudo Random Noise sequence with varying time spacings to detect spoofing by calculating a shape anomaly factor, which signals the detection of a spoofed signal and allows for reacquisition of the original satellite signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple antenna array is used to detect GPS spoofing, then spoofing detection capability is improved, but device complexity and hardware requirements increase
Solution Approach 1:
The patent creates a virtual copy of the tracking channel by generating multiple replicas of the Pseudo Random Noise sequence with different time spacings. This virtual replica system allows spoofing detection without requiring additional physical antenna arrays, thus improving detection capability while avoiding increased hardware complexity
Solution Approach 2:
The patent replaces the mechanical approach of using additional physical antenna arrays with a software-based signal processing approach. By substituting physical hardware with computational methods (generating multiple PRN sequence replicas and analyzing correlation patterns), the system achieves spoofing detection without the corresponding hardware overhead
2Reliability
If Parallel Least Mean Square calculation with multiple constellations is used, then spoofing detection is improved, but the system can only act after spoofing attack occurs and requires multifrequency/parallel positioning
Solution Approach 1:
The patent performs preliminary action by continuously generating multiple replicas of the Pseudo Random Noise sequence with different time spacings and continuously monitoring correlation patterns. This allows the system to detect spoofing attacks in real-time as they occur, rather than waiting for post-attack analysis, thus reducing detection response time while maintaining reliability
3Reliability
If Navigation Message Authentication with Galileo PRS is used, then spoofing detection is improved, but the solution is not suitable for GPS-only receivers and requires encrypted navigation service
Solution Approach 1:
The patent creates a universal spoofing detection method that works across multiple GNSS constellations (GPS, Galileo, GLONASS, BeiDou) by using constellation-independent correlation analysis of PRN sequence replicas. This universal approach allows the same detection mechanism to function in GPS-only receivers without requiring Galileo PRS or encrypted navigation services, thus improving adaptability while maintaining reliability
Data Source
AI summary
An embodiment method comprises receiving a satellite signal in a tracking channel, generating a set of replicas of a pseudo random noise sequence, comprising a punctual replica and a plurality of replicas that are different in time with respect to the punctual replica over a given time spacing, correlating the received signal with each replica to obtain amplitude correlation values, monitoring the tracking channel to detect a spoofed signal by generating a further plurality of replicas of the pseudo random noise sequence having a respective time spacing greater than the given time spacing, correlating the received signal of the tracking channel with each further replica to obtain further amplitude correlation values, calculating a shape anomaly factor based on the further correlation amplitude values, verifying the shape anomaly factor is greater than a given shape anomaly threshold, and signaling detection of a spoofed signal on the tracking channel.