Standalone GNSS Spoofing Detection via Cross-Correlation Analysis
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Solution Overview
Problem
Current GNSS positioning techniques are vulnerable to jamming and signal spoofing attacks, which can lead to inaccurate positioning and pose safety risks, especially in autonomous vehicles, due to the lack of authentication and protection mechanisms.
Innovation Solution
A device and method that utilize an RF chain, analog-to-digital converter, and computer logic to calculate and analyze cross-correlation peaks over a grid of spreading code phase delays and Doppler shifts, detecting spoofing by monitoring the position and variation of these peaks across successive signal acquisitions, and providing information to the GNSS receiver to mitigate threats.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If cross-correlation peak analysis is performed over a grid of spreading code phase delays and Doppler shifts, then spoofing detection accuracy is improved, but device complexity increases
Solution Approach 1:
The patent segments the spoofing detection process into distinct functional modules: an RF chain for signal acquisition and downconversion, an analog-to-digital converter for digitization, and a computer logic unit for cross-correlation calculations. This segmentation allows each component to be optimized independently while maintaining overall system functionality.
Solution Approach 2:
The device is designed to work with existing GNSS receivers without requiring modifications to them, making the spoofing detection capability universal and applicable to multiple receiver types. The standalone device performs multiple functions including signal processing, cross-correlation analysis, and spoofing detection.
2Reliability
If monitoring of cross-correlation peak position is performed over successive signal acquisitions, then reliability of spoofing detection is improved, but loss of time increases
Solution Approach 1:
The patent performs cross-correlation calculations over a pre-defined grid of spreading code phase delays and Doppler shifts before final spoofing detection. This preliminary action prepares the data structure in advance, allowing for more reliable detection across successive acquisitions without excessive time delay.
Solution Approach 2:
The device continuously monitors cross-correlation peak positions over successive signal acquisitions, maintaining continuous useful action for spoofing detection. This continuous monitoring improves reliability by detecting patterns across multiple acquisitions while managing time loss through efficient processing.
3Ease of operation
If the device processes signals without altering existing GNSS receivers, then ease of operation is improved, but device complexity increases
Solution Approach 1:
The patent introduces a standalone spoofing detection device that acts as an intermediary between the GNSS antenna and the existing receiver. This intermediary device processes the signal and provides spoofing detection information without requiring modifications to the existing receiver, thereby improving ease of operation.
Solution Approach 2:
The device performs self-service by independently acquiring and processing GNSS signals through its own RF chain and computer logic, without requiring external assistance or modifications to other systems. This self-contained design simplifies operation while encapsulating the necessary complexity within the device itself.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively detects spoofing situations without altering existing GNSS receivers, reducing false alarms and improving the robustness against multipath reflections, enabling timely countermeasures against spoofing attempts.
Implementation Method 1
an RF chain to acquire and down convert a signal comprising one or more GNSS signals
Implementation Method 2
an analog to digital converter, to digitize the down converted signal
Implementation Method 3
calculate over a grid of spreading code phase delays and Doppler shifts, cross-correlation functions between said digitized signal and locally generated replicas of the signal
Implementation Method 4
cross-correlation functions between said digitized signal and locally generated replicas of the signal, for one or more of said spreading codes... over a grid of spreading code phase delays and Doppler shifts
Data Source
AI summary
A device and the associated method for detecting spoofing of GNSS signals are provided. The device includes an RF chain to acquire and down convert a signal comprising one or more GNSS signals transmitted by GNSS sources, each of the GNSS signals comprising a navigation message modulated by a spreading code associated to a related GNSS source, an analog to digital converter, to digitize the down converted signal, and a computer logic, to: calculate over a grid of spreading code phase delays and Doppler shifts, cross-correlation functions between the digitized signal and locally generated replicas of the signal, for one or more of the spreading codes, identify cross-correlation peaks, and analyze the cross-correlation peaks to detect spoofing situations.