GNSS Receiver Spoofing Detection via Noise Floor and Phase Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing GNSS receivers lack effective methods to detect spoofed signals in real-time, particularly in multi-frequency and multi-constellation environments, which can lead to inaccurate positioning and decision-making in critical applications like autonomous driving.
Innovation Solution
A method and system that determine satellite signal noise floor and phase noise values for each tracking channel, comparing these values to established thresholds to detect spoofed signals. This approach involves implementing a satellite tracking channel with a frequency loop and using signal processing circuitry to analyze noise floor and phase noise metrics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing GNSS receivers use traditional positioning methods, then positioning function is provided, but they lack effective spoofing detection capability leading to inaccurate positioning under spoofing attacks
Solution Approach 1:
The patent segments the spoofing detection function into separate modules within the receiver: a noise floor detection unit that monitors signal noise levels, a phase error detection unit that tracks phase deviations, and a decision unit that compares these measurements against thresholds. This modular segmentation enables spoofing detection without requiring a complete redesign of the receiver architecture.
Solution Approach 2:
The patent implements preliminary detection actions by continuously monitoring noise floor and phase error metrics before spoofing can fully compromise positioning. The receiver proactively compares these parameters against pre-established thresholds to detect spoofing attempts in real-time, preventing inaccurate positioning rather than correcting it afterward.
2Reliability
If spoofing detection is added to existing receivers, then detection capability is improved, but real-time detection performance deteriorates due to processing delays
Solution Approach 1:
The patent replaces complex computational spoofing detection methods with simpler signal parameter measurements. Instead of performing heavy signal processing or authentication computations, the system substitutes mechanical-like direct measurements of noise floor and phase error, which can be computed rapidly with minimal processing overhead, enabling real-time detection.
Solution Approach 2:
The patent changes the detection parameters from complex signal characteristics to fundamental receiver parameters that are already being monitored for positioning: noise floor level and phase error. By utilizing these existing parameters for spoofing detection, the system achieves real-time performance without adding significant processing burden.
3Reliability
If multiple constellations are used for independent position identification, then spoofing detection is improved, but system complexity and hardware requirements increase
Solution Approach 1:
The patent makes the existing tracking channels multi-functional by enabling them to perform both positioning and spoofing detection simultaneously. The same signal processing paths that extract position information also measure noise floor and phase error parameters, allowing a single receiver configuration to serve dual purposes without additional hardware.
Solution Approach 2:
The patent enables the receiver to self-diagnose spoofing conditions using its own internal measurements. The receiver monitors its tracking channel parameters (noise floor, phase error) and autonomously detects spoofing without requiring external reference systems or additional authentication infrastructure, making the system self-sufficient for anti-spoofing.
4Reliability
If navigation message authentication (Galileo PRS) is implemented, then spoofing detection is improved, but compatibility with other GNSS systems is reduced
Solution Approach 1:
The patent changes the detection approach from message-content authentication (which is system-specific) to physical signal parameter measurement (noise floor and phase error). These physical parameters are universal across all GNSS systems regardless of modulation scheme or message format, enabling the same detection methodology to work with GPS, Galileo, GLONASS, and other constellations.
Solution Approach 2:
The patent creates a universal spoofing detection mechanism that functions across multiple GNSS systems by relying on common receiver operations. Since all GNSS receivers perform carrier tracking and measure signal power and phase, this detection method is universally applicable without requiring system-specific authentication protocols or encrypted message processing.
Data Source
AI summary
A satellite tracking channel has a frequency loop tracking a carrier frequency of a satellite signal. A first indication of a spoofed signals is generated based on a determined satellite signal noise floor value associated with the satellite tracking channel and a tracking channel signal noise threshold associated with the satellite tracking channel. A second indication of a spoofed signal is generated based on a determining satellite tracking phase noise associated with the satellite tracking channel and a tracking channel phase noise threshold associated with the satellite tracking channel. Reception of a spoofed signal on the satellite tracking channel is detected based on the generated first indication of a spoofed signal and the generated second indication of the spoofed signal.