Virtual PIM Measurement for Base Station Signal Integrity

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Solution Overview

Problem

Current PIM measurement techniques, such as the IEC 62037 2-tone signal test, require expensive external equipment and disrupt live traffic, making it impractical for real-time estimation and mitigation in cellular base stations, especially in multi-band and co-sited scenarios.

Innovation Solution

A method and apparatus for estimating PIM in real-time using a software model that adapts to regular transmitted signals, allowing for remote monitoring and mitigation without dedicated equipment, by refining coefficients using algorithms like LMS or RLS to simulate the standardized two-tone test results.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the standardized IEC 62037 2-tone signal test is used for PIM measurement, then measurement precision is improved, but device complexity and cost increase due to requiring expensive external equipment

Engineering Contradiction:
ImprovePIM measurement precisionVSAvoidmeasurement equipment complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent creates a virtual copy of the standardized 2-tone test by using software-based signal generation and processing. Instead of requiring physical external equipment to generate test tones, the system generates equivalent test signals through software models that replicate the standardized measurement conditions, thereby achieving the same measurement precision without the associated hardware complexity and cost

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent replaces the mechanical/physical measurement system (external signal generators, power amplifiers, and spectrum analyzers required by IEC 62037) with a software-based virtual measurement system. The software model generates test tones, processes received signals, and calculates PIM values algorithmically, substituting physical measurement hardware with computational processes that achieve equivalent measurement precision

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

2Measurement precision

If the standardized IEC 62037 2-tone signal test is used for PIM measurement, then measurement precision is improved, but productivity decreases due to disruption of live traffic

Engineering Contradiction:
ImprovePIM measurement precisionVSAvoidbase station operational efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent performs preliminary signal processing and PIM calculation using existing traffic signals before any measurement disruption can occur. By continuously analyzing live traffic signals and pre-calculating PIM values from the received signal components, the system maintains measurement precision while avoiding the need to interrupt service for dedicated test measurements

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent enables continuous PIM measurement throughout base station operation by processing live traffic signals in real-time. Instead of performing discrete measurements that interrupt service, the system continuously analyzes incoming signals and updates PIM calculations without breaking the continuity of useful communication actions, thereby maintaining both measurement precision and operational productivity

Inventive Principle:
Principle #20Continuity of useful action

3Measurement precision

If external equipment is used for PIM measurement, then measurement precision is improved, but ease of operation deteriorates due to complexity of setup and execution

Engineering Contradiction:
ImprovePIM measurement precisionVSAvoidPIM measurement operation simplicity
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent merges the PIM measurement functionality with the existing base station signal processing chain. By integrating test signal generation, signal reception, and PIM calculation into the same software platform that handles normal communication operations, the system achieves standardized measurement precision while eliminating the need for separate external equipment setup and coordination

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent creates a universal software-based measurement platform that handles both normal communication signal processing and PIM measurement functions through a single integrated system. This multi-functional approach allows the base station to perform standardized PIM measurements with the same equipment used for regular operations, greatly simplifying the ease of operation while maintaining measurement precision through adherence to IEC 62037 standards

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3808014B1Generalized virtual PIM measurement for enhanced accuracy
Publication Date: 2024.04.17 NOKIA TECHNOLOGIES OY
  • EP3808014B1 patent drawingFigure 1~2
  • EP3808014B1 patent drawingFigure 3~5
  • EP3808014B1 patent drawingFigure 6~7

AI summary

An apparatus, method and work product is disclosed. The method comprises measuring plural transmit signals and corresponding receive signals and determining, using a model describing a relation between each of the plural transmit signals and a respective passive intermodulation signal, a standardized passive intermodulation signal as one or more nth order intermodulation products for a standardized transmit signal consisting of two tones each of a power of substantially 20 Watts. The method may also comprise identifying in the model one or more nth order cross-intermodulation products resulting from three or more transmit signals having different respective carrier frequencies. Responsive to the identification, the method may comprise adapting the standardized two-tone passive intermodulation signal by determining an offset for producing an adapted two-tone standardized passive intermodulation signal, n is an odd integer greater than two.