LTE-U Channel State Information Feedback via Resource Unit Grouping

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Solution Overview

Problem

LTE-U nodes deployed in unlicensed frequency bands face interference challenges, as existing methods using joint channel estimation and CSI feedback fail to accurately reflect interference variations over time, leading to inefficient data transmission.

Innovation Solution

User equipment generates and sends channel state information specific to each resource unit, allowing the base station to accurately assess and mitigate interference by associating CSI with corresponding resource units, thereby improving data transmission efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If joint channel estimation is performed on the entire channel, then the overhead associated with feedback is reduced, but the interference suffered by the base station when sending data cannot be faithfully reflected

Engineering Contradiction:
Improvefeedback overheadVSAvoidinterference reflection accuracy
Core Design Contradiction:
Loss of informationVSMeasurement precision

Solution Approach 1:

The patent divides the entire channel into multiple resource units (sub-channels) and performs separate channel estimation for each resource unit. The user equipment sends separate CSI feedback for each resource unit, allowing the base station to accurately reflect interference conditions for each specific resource unit while maintaining manageable feedback overhead through structured reporting.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If separate channel estimation is performed for each resource unit, then interference reflection accuracy is improved, but the feedback overhead increases

Engineering Contradiction:
Improveinterference reflection accuracyVSAvoidfeedback overhead
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent combines multiple resource units with similar interference characteristics into resource unit groups. The user equipment performs joint estimation within each group and sends one CSI feedback per group, reducing the total number of feedback messages while maintaining accurate interference reflection for each resource unit through the grouping strategy.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent changes the feedback parameter structure by introducing resource unit group identifiers and group-level CSI parameters. Instead of sending individual CSI for each resource unit, the system uses group-based parameters that capture the essential interference characteristics multiple resource units share, thereby reducing feedback overhead while preserving measurement precision.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If CSI is sent for the entire channel, then device complexity is reduced, but adaptability to different interference conditions in different time periods deteriorates

Engineering Contradiction:
Improveprocessing complexityVSAvoidinterference adaptation
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic resource unit grouping where groups are formed based on current interference conditions and can be reconfigured over time. The base station can adjust the grouping strategy according to varying interference patterns in different time periods, allowing the system to adapt to changing channel conditions while keeping processing complexity manageable through the structured grouping approach.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3179797B1Data transmission methods and devices
Publication Date: 2020.02.12 HUAWEI TECH CO LTD
  • EP3179797B1 patent drawingFigure 1~2
  • EP3179797B1 patent drawingFigure 3~5
  • EP3179797B1 patent drawingFigure 6~8

AI summary

Embodiments of the present invention provide a data transmission method and system, and a device, applying to the field of communications technologies. The data transmission method includes: generating, by user equipment, at least one piece of channel state information, wherein each piece of channel state information in the at least one piece of channel state information is corresponding to at least one resource unit required for sending data by a base station; and sending, by the user equipment, multiple pieces of channel state information, so that the base station sends data on a corresponding resource unit according to channel state information. Therefore, channel state information sent by the user equipment is associated with a resource unit required for sending data by the user equipment.