RF Signal Spoofing Detection via Power Spectral Density Analysis

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Radio frequency (RF) signals, such as GPS signals, are vulnerable to jamming and spoofing due to their weak amplitudes relative to noise and interference, making them difficult to detect, especially in scenarios where intentional interference or false signals are introduced.

Innovation Solution

A radio frequency receiver system that includes an antenna and an RF signal front-end to generate an equivalent digital signal, which is then processed to analyze the power spectral density (PSD) and compared to a predetermined baseline PSD to detect the presence of spoofing signals, utilizing discrete Fourier transform and normalization to enhance detection accuracy and insensitivity to amplitude variations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If RF signal amplitude is increased to improve detection, then signal detectability is improved, but susceptibility to jamming and spoofing increases

Engineering Contradiction:
Improvesignal detection capabilityVSAvoidvulnerability to jamming and spoofing
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary characterization of legitimate RF signals by capturing and storing their spectral properties (power spectral density, cyclic spectral density, higher-order spectral density) before actual detection occurs. This pre-established reference data enables later comparison to identify spoofing attempts without requiring amplitude increases that would attract jammers.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system transforms the RF signal from the time domain to the frequency domain and analyzes its spectral 'color' or characteristics. By examining power spectral density, cyclic spectral density, and higher-order spectral density, the system identifies unique spectral fingerprints of legitimate signals versus spoofed signals, enabling detection based on spectral properties rather than amplitude.

Inventive Principle:
Principle #32Color changes

2Device complexity

If conventional detection methods are used, then system simplicity is maintained, but detection accuracy against sophisticated spoofing is insufficient

Engineering Contradiction:
Improvedetection system complexityVSAvoidspoofing detection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The system moves detection from the traditional time-domain amplitude analysis to the frequency domain and beyond by incorporating cyclic spectral density and higher-order spectral density analysis. This dimensional transformation provides additional degrees of freedom for distinguishing legitimate signals from spoofed signals, improving detection accuracy without requiring proportionally increased system complexity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The system combines multiple spectral analysis techniques (power spectral density, cyclic spectral density, higher-order spectral density) into a composite detection approach. By integrating these different spectral characteristics, the system creates a robust multi-dimensional fingerprinting system that can reliably distinguish legitimate RF signals from spoofing attempts, achieving high detection accuracy through the synergistic combination of multiple analysis methods.

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP2792021B1System and method for detection of RF signal spoofing
Publication Date: 2017.02.08 NORTHROP GRUMMAN GUIDANCE AND ELECTRONICS CO INC
  • EP2792021B1 patent drawing
  • EP2792021B1 patent drawing
  • EP2792021B1 patent drawing

AI summary

One embodiment of the invention includes a radio frequency (RF) receiver system. The system includes an antenna configured to receive an RF input signal and an RF signal front-end system configured to process the RF input signal to generate an equivalent digital signal. The system also includes a spoof detection system configured to analyze a power spectral density (PSD) of the equivalent digital signal and to compare the PSD of the equivalent digital signal with a predetermined baseline PSD to detect the presence of a spoofing signal component in the RF input signal.