Channel Measurement Method Reducing Feedback Overhead

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Solution Overview

Problem

The high overheads associated with feeding back subband Channel State Information (CSI) in wireless communication systems, which can significantly impact transmission quality due to the large amount of data that needs to be transmitted.

Innovation Solution

Reducing feedback overheads by only reporting CSI for some subbands and using a reference rule to generate CSI for other subbands, ensuring consistency between the receive and transmit end devices, thereby minimizing adverse effects on transmission quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If subband CSI is fed back for all subbands, then transmission quality is improved, but feedback overheads increase significantly

Engineering Contradiction:
Improvetransmission qualityVSAvoidfeedback overheads
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent segments the frequency band into multiple subbands and selectively reports CSI only for certain subbands (e.g., subbands with significant channel variations or specific importance) rather than all subbands. This segmentation approach maintains transmission quality for critical frequency regions while reducing overall feedback overhead by excluding less important subbands from the report.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts and reports only the essential or most significant CSI components from the full set of subband measurements. By identifying and extracting key channel state information (such as CSI for subbands with high variance or specific priority subbands) and omitting redundant information, the system achieves acceptable transmission quality with reduced feedback overhead.

Inventive Principle:
Principle #2Taking out (Extraction)

2Measurement precision

If CSI for all subbands is reported, then channel state information accuracy is improved, but feedback data volume increases

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

Solution Approach 1:

The patent applies local quality by differentiating the reporting treatment of different subbands based on their individual characteristics. Instead of uniform reporting, the system identifies subbands with specific properties (e.g., high channel variation, interference, or importance) and reports CSI selectively for those local regions, thereby maintaining measurement precision where needed while reducing overall data volume.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent implements partial action by reporting CSI for only a subset of subbands rather than all subbands. The system determines that reporting CSI for all subbands would be excessive, and instead selectively reports for critical subbands, achieving sufficient channel state information accuracy for effective transmission without the burden of complete subband reporting.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3672317B1Method for channel measurement
Publication Date: 2023.11.01 HUAWEI TECH CO LTD
  • EP3672317B1 patent drawingFigure 1
  • EP3672317B1 patent drawingFigure 2
  • EP3672317B1 patent drawingFigure 3~4

AI summary

Embodiments of the present invention provide a channel measurement method. The method includes: obtaining, for a to-be-measured frequency band including at least one reporting subband and at least one missing subband, channel state information of each reporting subband and channel state information of each missing subband, where the channel state information of each reporting subband is obtained based on channel estimation, and the channel state information of each missing subband is obtained according to a reference rule with reference to channel state information of a reporting subband that is indicated by the reference rule and that is in the at least one reporting subband; 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 each reporting subband in the at least one reporting subband. The present invention helps reduce feedback overheads brought by channel measurement, and helps implement consistency of the channel state information between a receive end device and the transmit end device, to avoid adverse impact on a transmission effect.