Dynamic MPR Calculation for Multi-Cluster LTE Intermodulation

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Solution Overview

Problem

Current wireless communication systems, such as LTE, face challenges in managing intermodulation distortion products, leading to increased out-of-band emissions and reduced network performance due to stringent maximum power reduction requirements, especially in multi-cluster transmissions.

Innovation Solution

The method involves determining the spectral positions of intermodulation distortion products and mapping them to corresponding spectral regions to calculate a maximum power reduction value, which is based on the number of resource blocks and additional criteria like gap and balance information, thereby mitigating unnecessary power reductions and improving UE throughput and network capacity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If maximum power reduction is applied to meet out-of-band emissions requirements in multi-cluster transmissions, then spectral emission compliance is improved, but network performance and capacity deteriorate due to unnecessary power reductions

Engineering Contradiction:
Improveout-of-band emissionsVSAvoidnetwork capacity
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent changes the parameter of power reduction determination from a fixed approach to a dynamic approach based on intermodulation distortion product locations. By calculating and identifying where intermodulation distortion products fall relative to transmitted clusters, the system adjusts power reduction requirements selectively - applying reductions only when distortion products fall within transmitted bands, and avoiding reductions when they fall in guard bands or empty regions, thus optimizing network capacity while meeting emission requirements

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements a feedback mechanism where the network calculates intermodulation distortion product locations based on uplink resource block allocations and feeds back appropriate power reduction indications to user equipment. This feedback loop allows the system to adapt power reduction requirements in real-time based on actual transmission configurations, preventing unnecessary power reductions and maintaining optimal network performance

Inventive Principle:
Principle #23Feedback

2Object-affected harmful factors

If maximum power reduction is applied to meet out-of-band emissions requirements in multi-cluster transmissions, then spectral emission compliance is improved, but UE throughput deteriorates due to reduced transmit power

Engineering Contradiction:
Improveout-of-band emissionsVSAvoidUE throughput
Core Design Contradiction:
Object-affected harmful factorsVSPower

Solution Approach 1:

The patent dynamically adjusts the power reduction parameter based on the calculated locations of intermodulation distortion products. When distortion products fall outside transmitted resource blocks (in guard bands or empty regions), no power reduction is applied, maintaining UE throughput. When distortion products fall within transmitted bands, selective power reduction is applied only to affected resource blocks, minimizing impact on overall throughput while meeting emission requirements

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If simplified power reduction rules are used for multi-cluster transmissions, then device complexity is reduced, but measurement precision of intermodulation distortion products deteriorates

Engineering Contradiction:
Improvepower control complexityVSAvoiddistortion product location accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent segments the frequency spectrum into distinct regions - transmitted resource blocks, guard bands, and empty regions - and calculates intermodulation distortion product locations relative to these segments. This segmentation approach provides precise location determination without requiring complex overall system analysis, as each distortion product can be independently evaluated against the segmented spectral map

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary calculation of intermodulation distortion product locations based on known resource block allocations before determining power reduction requirements. By pre-calculating where distortion products will fall given the scheduled transmissions, the system achieves accurate measurement without requiring complex real-time analysis during power control decisions

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2904708B1Determining maximum power reduction (MPR) for multi-cluster wireless transmissions
Publication Date: 2018.11.14 QUALCOMM INC
  • EP2904708B1 patent drawingFigure 1
  • EP2904708B1 patent drawingFigure 2
  • EP2904708B1 patent drawingFigure 3

AI summary

A method of wireless communication includes determining spectral positions of intermodulation distortion products for a multi-cluster transmission. The method also includes mapping the spectral positions to corresponding spectral regions. The method further includes determining a maximum power reduction value of the multi-cluster transmission based on the corresponding spectral regions.