Selective Subband CSI Reporting for Wireless Feedback Overhead Reduction

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Solution Overview

Problem

Current channel measurement technologies face high feedback overheads when transmitting subband Channel State Information (CSI) in wireless communication systems, particularly when a large amount of subband CSI needs to be fed back.

Innovation Solution

The proposed solution reduces feedback overheads by selectively reporting CSI from only some subbands, which can be either contiguous or non-contiguous in the frequency domain, allowing for flexible subband selection and configuration using reporting subband configuration information or grouping schemes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If subband CSI is transmitted for all subbands, then channel state information accuracy is improved, but feedback overhead increases

Engineering Contradiction:
Improvechannel state information accuracyVSAvoidfeedback overhead
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent divides the frequency band into multiple subbands and applies different reporting strategies to different subbands. Some subbands report full CSI while others report reduced or no CSI, segmenting the reporting burden based on channel characteristics and interference conditions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements local quality by allowing different subbands to have different reporting configurations. Subbands with high interference or important channel characteristics can maintain higher reporting quality, while subbands with good channel conditions can reduce reporting overhead.

Inventive Principle:
Principle #3Local quality

2Quantity of substance

If subband CSI is selectively reported from only some subbands, then feedback overhead is reduced, but channel state information completeness deteriorates

Engineering Contradiction:
Improvefeedback overheadVSAvoidchannel state information completeness
Core Design Contradiction:
Quantity of substanceVSLoss of information

Solution Approach 1:

The patent performs preliminary actions by configuring subband grouping and reporting patterns in advance based on channel statistics and interference characteristics. This allows the system to pre-determine which subbands need detailed reporting and which can use reduced reporting, preventing information loss in critical subbands.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses feedback mechanisms where the receiver evaluates channel conditions and provides feedback to the transmitter about which subbands require detailed CSI reporting. This adaptive feedback loop ensures that critical channel information is maintained while reducing overhead for less critical subbands.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3609114B1Channel measurement method and apparatus
Publication Date: 2023.08.30 HUAWEI TECH CO LTD
  • EP3609114B1 patent drawingFigure 1
  • EP3609114B1 patent drawingFigure 2
  • EP3609114B1 patent drawingFigure 3

AI summary

Embodiments of the present invention provide a channel measurement method and an apparatus. The method includes: for a to-be-measured frequency band that includes at least one reporting subband and 0 or more non-reporting subbands, obtaining channel state information of each reporting subband, where the channel state information of each reporting subband is obtained based on channel estimation, and the at least one reporting subband is included in reporting subbands that are contiguous in frequency domain, or the at least one reporting subband is included in reporting subbands that are not contiguous in frequency domain; and sending a measurement report of the to-be-measured frequency band to a transmit end device, where the measurement report includes the channel state information of one or more of the at least one reporting subband. The present invention helps reduce feedback overheads caused by channel measurement, and helps implement consistency of the channel state information between a receive end device and the transmit end device, thereby avoiding adverse impact on a transmission effect.