Satellite Signal Processing for Multi-Tone Jamming Detection

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Solution Overview

Problem

Satellite positioning systems (SPS) face challenges in accurately detecting pseudorange measurements due to interference from multipath and jamming signals, which can lead to false alarms and hinder the detection of valid correlation peaks, especially in environments with high signal attenuation such as indoors.

Innovation Solution

The implementation of techniques to detect and reject energy caused by single-tone and multi-tone jammers by identifying uniform and non-uniform energy ridges in the code phase search window, allowing for the alteration of signal processing to reduce false alarms and improve the accuracy of pseudorange measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If signal processing is performed to detect correlation peaks in SPS signals, then position location accuracy can be achieved, but false alarms occur due to multipath and jamming signals

Engineering Contradiction:
Improvepseudorange measurement accuracyVSAvoidfalse alarm rate
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The code phase search window is divided into multiple segments, with each segment processed independently to identify energy peaks. This segmentation allows the system to detect and reject jamming signals that appear as localized energy ridges while preserving valid correlation peaks from genuine SPS signals.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

An energy detection mechanism serves as an intermediary between the raw correlation output and the final pseudorange measurement. This intermediary layer identifies and flags energy ridges caused by jamming signals, allowing the system to filter out false alarms before they affect position calculation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If standard correlation processing is used to detect SPS signals, then valid correlation peaks can be identified, but detection fails in high signal attenuation environments such as indoors

Engineering Contradiction:
Improvesignal detection accuracyVSAvoidsignal attenuation
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The system extracts and removes energy ridge components from the correlation output that are caused by jamming signals. By taking out these harmful energy ridges, the system can then more easily detect weak valid correlation peaks that would otherwise be buried in the noise floor, especially in attenuated indoor environments.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system performs preliminary energy detection and jamming signal identification before final correlation peak detection. By preemptively identifying and rejecting jamming-induced energy ridges, the system prepares a cleaner signal environment that enhances the detectability of weak valid signals in high-attenuation scenarios.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If energy detection is performed across the entire code phase search window, then jamming signals can be detected, but processing complexity increases

Engineering Contradiction:
Improvejamming detection capabilityVSAvoidsignal processing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The code phase search window is segmented into multiple smaller segments, reducing the computational burden of energy detection in each segment. This segmentation strategy maintains comprehensive jamming detection capability while significantly lowering overall processing complexity compared to analyzing the entire search window as a single unit.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2288931B1System and/or method for detecting multi-tone jamming
Publication Date: 2018.11.14 QUALCOMM INC
  • EP2288931B1 patent drawingFigure 1
  • EP2288931B1 patent drawingFigure 2A~2C
  • EP2288931B1 patent drawingFigure 3

AI summary

The subject matter disclosed herein relates to a system and method for processing a signal received from a satellite positioning system (SPS) in the presence of a mulit-tone jammer. In one particular implementation, processing of a signal may be altered in response to detection of one or more conditions.