GNSS Signal Processing Attenuating Jamming via Covariance Analysis
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Solution Overview
Problem
Satellite positioning systems, such as GPS and GLONASS, are vulnerable to interference from jammers, which can disrupt navigation signals and pose risks to civilian and military operations, and existing anti-jamming solutions are inadequate in effectively mitigating these interferences.
Innovation Solution
A method for processing satellite navigation signals using an array of antennas that involves detecting jamming signals by analyzing the covariance matrix of received signals, performing singular value decomposition, and applying weighting coefficients to attenuate interference, thereby optimizing the signal from the satellite of interest.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional anti-jamming solutions are used, then some interference mitigation is achieved, but the solutions are inadequate in effectively mitigating jamming signals
Solution Approach 1:
The patent performs preliminary identification of jamming signal directions by analyzing the covariance matrix and detecting eigenvalues before the actual signal processing. This preliminary detection step allows the system to pre-determine which directions contain jamming signals, so that subsequent weighting and attenuation can be applied more effectively and efficiently to those specific directions.
Solution Approach 2:
The patent changes the parameters of the antenna array by dynamically adjusting the weighting coefficients applied to signals from different antenna elements. By modifying these weights based on the identified jamming directions, the system alters the effective radiation pattern to create nulls in the directions of jamming signals, thereby attenuating them while maintaining sensitivity to satellite signals.
2Object-affected harmful factors
If signal processing is performed to attenuate jamming signals, then interference is reduced, but the detection precision of jamming signal direction must be high
Solution Approach 1:
The patent replaces direct spatial filtering mechanisms with a mathematical approach based on covariance matrix analysis and eigenvalue decomposition. Instead of using complex physical beamforming hardware, the system uses signal processing mathematics to identify jamming directions by detecting anomalies in the eigenvalue spectrum, thereby achieving accurate direction detection through computational methods.
Solution Approach 2:
The patent implements a feedback mechanism where the detected jamming directions are continuously fed back into the signal processing chain to adjust the weighting coefficients. This closed-loop approach allows the system to refine its estimation of jamming directions and continuously optimize the attenuation, improving both detection accuracy and interference rejection over time.
Data Source
AI summary
The invention relates to a method for processing a radio navigation signal originating from a satellite (SAT) and received by a radio navigation receiver comprising a plurality of receive antennas, each antenna being configured to receive signals originating from a satellite of interest (SAT), from at least one jammer and possibly from at least one other satellite (SAT′) in given directions, the method comprising the following steps: detecting (E1), on the basis of the signal received by each antenna, at least one direction of a jamming signal; attenuating (E2, E2′) the detected jamming signal in the detected direction; in which method detecting (E1) the direction of a jamming signal is based on determining a covariance matrix dependent on the signals received by each antenna given by (i), where Z is a matrix of size N×M in which each column corresponds to the signal received by each antenna, N denoting the number of samples acquired during a fixed period ΔT and M being the number of antennas.