Cyclostationarity Detection for Intermodulation Distortion Identification

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Solution Overview

Problem

Intermodulation distortion, particularly passive intermodulation distortion (PIM), is difficult to identify in communication networks, causing signal interference and reducing network throughput, and existing methods are costly and time-consuming, requiring network downtime for diagnosis.

Innovation Solution

The use of cyclostationarity detection techniques, including cyclic autocorrelation and spectral correlation density analysis, to identify and classify signals affected by intermodulation distortion, allowing for the detection of PIM in RF signals and communication systems, even in the presence of non-linear channel effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional diagnostic methods are used to identify intermodulation distortion, then measurement precision can be achieved, but loss of time and productivity are significantly worsened due to network downtime requirements

Engineering Contradiction:
Improveintermodulation distortion detection accuracyVSAvoidnetwork downtime
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system enables self-service by having the communication network automatically monitor and detect intermodulation distortion using cyclostationarity analysis on existing traffic signals, eliminating the need for external diagnostic equipment and network downtime. The network detects PIM conditions autonomously through continuous signal analysis.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system maintains continuity of useful action by performing intermodulation distortion detection on ongoing communication traffic without interrupting service. The cyclostationarity analysis is applied continuously to live signals, allowing detection while the network remains operational and productive.

Inventive Principle:
Principle #20Continuity of useful action

2Measurement precision

If traditional diagnostic methods are used to identify intermodulation distortion, then measurement precision can be achieved, but device complexity and operational costs are significantly worsened

Engineering Contradiction:
Improveintermodulation distortion detection accuracyVSAvoiddiagnostic equipment complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system uses cyclostationarity analysis as an intermediary mathematical tool that transforms the complex problem of PIM detection into a simpler signal processing task. By analyzing cyclic statistical properties of signals, the system avoids the need for complex physical diagnostic equipment while maintaining detection accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system replaces mechanical/physical diagnostic equipment with signal processing algorithms. Instead of using sophisticated hardware to inject test signals and physically inspect components, the invention uses mathematical analysis of existing electromagnetic signals to detect intermodulation distortion.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If traditional diagnostic methods are used to identify intermodulation distortion, then measurement precision can be achieved, but ease of operation is significantly worsened

Engineering Contradiction:
Improveintermodulation distortion detection accuracyVSAvoiddetection process simplicity
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The system enables self-service by having the communication network automatically monitor and detect intermodulation distortion using cyclostationarity analysis on existing traffic signals, eliminating the need for external diagnostic equipment and network downtime. The network detects PIM conditions autonomously through continuous signal analysis.

Inventive Principle:
Principle #25Self-service

4Productivity

If cyclostationarity detection is applied to existing traffic signals, then productivity is improved by avoiding network downtime, but difficulty of detecting and measuring is worsened due to signal complexity

Engineering Contradiction:
Improvenetwork operational continuityVSAvoidsignal analysis complexity
Core Design Contradiction:
ProductivityVSDifficulty of detecting and measuring

Solution Approach 1:

The system changes the measurement parameters by shifting from analyzing raw signal amplitudes or frequencies to analyzing cyclostationarity parameters such as cyclic autocorrelation and spectral correlation density. This transformation simplifies the detection process by converting a complex physical problem into a standardized statistical analysis that can be performed on existing traffic signals.

Inventive Principle:
Principle #35Parameter changes

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

Enables efficient and timely identification of intermodulation distortion, reducing network downtime and operational costs by detecting PIM through cyclostationary properties analysis, thereby improving signal quality and network performance.

Implementation Method 1

The use of cyclostationarity detection techniques, including cyclic autocorrelation and spectral correlation density analysis, to identify and classify signals affected by intermodulation distortion

Methodology Applied
Scientific EffectCyclostationarity:

Data Source

PatentEP2932606B1System and method for cyclostationarity-based intermodulation identification
Publication Date: 2020.07.01 COMMSCOPE TECHNOLOGIES LLC
  • EP2932606B1 patent drawingFigure 1
  • EP2932606B1 patent drawingFigure 2
  • EP2932606B1 patent drawingFigure 3

AI summary

The present disclosure describes systems and methods for identifying a signal that is a product of two or more other signals, ie intermodulation distortion. In an embodiment, the presence of a particular signal is determined and identified by applying a cyclostationarity detection technique, such as comparing a cyclic autocorrelation function of a product signal with the cyclic autocorrelation function of at least one of the signals which formed the product signal.