Cellular CQI Feedback with Reference–Data Power Correction

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Solution Overview

Problem

The existing methods for measuring channel quality indicator (CQI) in cellular systems, particularly in large-scale MIMO environments, face inaccuracies due to differences in received power between reference signals and data signals from serving and neighbor base stations, leading to incorrect interference condition assessments.

Innovation Solution

An apparatus and method that calculates CQI based on measuring reference signals from both serving and neighbor base stations, considering the power difference between these signals, and provides feedback to the serving base station to improve accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Difficulty of detecting and measuring

If CQI is calculated based on reference signal measurements only, then the measurement process is simple, but the interference condition assessment becomes inaccurate due to power differences between reference signals and data signals

Engineering Contradiction:

Improvemeasurement process complexityVSAvoidinterference condition assessment accuracy

Core Design Contradiction:

Difficulty of detecting and measuringVSMeasurement precision

Solution Approach 1:

The patent introduces a power difference parameter (Pc) that quantifies the difference between reference signal power and data signal power. By incorporating this parameter into the CQI calculation, the system transforms the measurement approach from using reference signal power alone to using a corrected value that accounts for the power difference, thereby improving measurement precision without significantly increasing complexity

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses the power difference parameter Pc as an intermediary element that bridges the gap between reference signal measurements and actual data signal interference conditions. This intermediary parameter allows the system to indirectly assess data signal interference by measuring reference signals and applying the power difference correction, resolving the contradiction between measurement simplicity and accuracy

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If beamforming with large number of antenna elements is used, then the capacity of cellular system increases significantly, but the difference between received power of reference signal and data signal becomes more pronounced

Engineering Contradiction:

Improvecellular system capacityVSAvoidCQI accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent addresses the power difference issue exacerbated by beamforming by introducing and applying the power difference parameter Pc. This parameter compensation mechanism allows the system to maintain accurate CQI measurements even when large-scale MIMO beamforming creates significant power variations between reference and data signals, thus preserving measurement precision while enabling high capacity

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS12355534B2Apparatus and method

Publication Date: 2025.07.08 SONY GROUP CORP

AI summary

[Object] To provide a mechanism capable of more appropriately ascertaining an interference condition of a data signal.[Solution] An apparatus includes: a processing unit that feeds back a channel quality indicator (CQI) of a serving base station, which is calculated on a basis of results of measuring reference signals received from the serving base station and a neighbor base station and information related to a power difference between the reference signal and a data signal of the neighbor base station, to the serving base station.