Remote Passive Intermodulation Detection and Cancellation

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Solution Overview

Problem

Passive intermodulation in wireless communication environments is difficult and costly to diagnose due to the need for site visits by skilled technicians to identify non-linearity sources, especially in external passive intermodulation caused by physical equipment and environmental factors.

Innovation Solution

A remote passive intermodulation detection system that generates test signals to identify and locate non-linearity sources by analyzing intermodulation products, distinguishing them from adjacent channel interference, and using these characteristics to cancel the effects of non-linearities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If site visits by skilled technicians are used to detect and identify non-linearity source locations, then diagnostic accuracy can be achieved, but the process becomes costly and time-consuming

Engineering Contradiction:

Improvediagnostic accuracyVSAvoidtime for site visits

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The system enables self-diagnosis of passive intermodulation sources by automatically cycling test signals through different sectors and analyzing intermodulation products, eliminating the need for technician site visits while maintaining diagnostic accuracy through automated detection and identification of non-linearity sources

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent replaces the mechanical process of technician site visits with an automated electronic system that transmits test signals, processes received signals, and automatically identifies intermodulation sources through digital signal analysis, thereby reducing time loss while preserving measurement precision

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If site visits by skilled technicians are used to detect and identify non-linearity source locations, then diagnostic accuracy can be achieved, but the process becomes costly

Engineering Contradiction:

Improvediagnostic accuracyVSAvoidcost of diagnosis

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The system performs self-diagnosis by automatically cycling test signals and analyzing intermodulation products without requiring skilled technicians, thereby maintaining diagnostic accuracy while eliminating the cost associated with technician deployment

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system uses test signals that replicate actual transmission conditions to generate intermodulation products, creating a model of the passive intermodulation sources that can be analyzed remotely without requiring physical presence at the site, thus reducing diagnostic costs while preserving accuracy

Inventive Principle:

Principle #26Copying

3Ease of operation

If test signals are transmitted to identify passive intermodulation sources, then remote diagnosis capability is achieved, but interference with customer connections must be avoided

Engineering Contradiction:

Improveremote diagnosis capabilityVSAvoidinterference with customer connections

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The system cycles test signals through different sectors in a periodic manner, transmitting test signals only during specific time intervals assigned to each sector, which enables remote diagnosis capability while minimizing interference with customer connections by limiting test signal transmission to scheduled periods

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The system divides the testing process into separate sector-specific test cycles, where test signals are transmitted to one sector at a time rather than simultaneously to all sectors, thereby enabling remote diagnosis while reducing overall interference with customer connections through temporal and spatial segmentation of test signal transmission

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS10039022B2Remote diagnosis and cancellation of passive intermodulation

Publication Date: 2018.07.31 AT&T INTELLECTUAL PROPERTY I L P

AI summary

A passive intermodulation detection system is provided to remotely identify passive intermodulation at a base station site and diagnose the type of intermodulation and location of the non-linearity that is the source of the passive intermodulation. The passive intermodulation detection system can generate a test signal in a first band that is transmitted by an antenna. Another antenna can receive a signal in another band, and the passive intermodulation detection system can analysis the received signal to determine whether an intermodulation product due to a non-linearity is present. Based on the type of intermodulation product, period, order, frequency, and etc., the type and location of the non-linearity can be identified.