Channel State Information Reporting via Comb Feedback

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Solution Overview

Problem

In coordinated multi-point transmission and carrier aggregation systems, the high volume of channel state information feedback occupies significant uplink channel bandwidth, leading to a heavy load on the uplink control channel and reduced spectral efficiency.

Innovation Solution

A method for reporting channel state information in a comb manner at set intervals, based on a numbering sequence, and determining feedback cycles according to importance parameters, reduces the feedback volume and optimizes channel state information reporting, using interpolation to calculate missing data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the terminal feeds back channel state information between the terminal and all possible serving points or sets, then the base station can complete the selection of the access point/set and scheduling of time frequency resources, but the feedback quantity increases greatly and occupies huge uplink channel bandwidth

Engineering Contradiction:
Improvechannel state information completenessVSAvoidfeedback quantity
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent segments the channel state information feedback by dividing the frequency band into multiple sub-bands and reporting CSI for different sub-bands at different time instances. This segmentation reduces the amount of feedback required at any single moment while ensuring complete channel state information is eventually obtained for all sub-bands.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements periodic feedback reporting where the terminal reports channel state information for different sub-bands in different reporting instances according to a predetermined pattern. This periodic action distributes the feedback load over time, reducing peak uplink bandwidth occupation while maintaining complete CSI availability.

Inventive Principle:
Principle #19Periodic action

2Adaptability or versatility

If the terminal feeds back channel state information for all component carriers in a carrier aggregation system, then the base station can perform coordinated multi-point transmission, but the uplink control channel load increases and spectral efficiency decreases

Engineering Contradiction:
Improvecoordinated multi-point transmission capabilityVSAvoidspectral efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent segments the feedback across multiple frequency sub-bands and time instances, so that not all component carrier CSIs need to be transmitted simultaneously. This segmentation maintains the adaptability for coordinated multi-point transmission while reducing the immediate uplink control channel load and improving spectral efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses periodic reporting instances to distribute the feedback of channel state information across different time slots. This periodic action ensures that the base station receives necessary CSI for coordinated multi-point transmission over time while reducing peak uplink traffic, thereby improving overall spectral efficiency.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP2416619B1Method for reporting channel state information, channel estimating method, terminal and base station
Publication Date: 2015.01.21 HUAWEI TECH CO LTD
  • EP2416619B1 patent drawingFigure 1~2
  • EP2416619B1 patent drawingFigure 3~4
  • EP2416619B1 patent drawingFigure 5~6

AI summary

A method for reporting channel state information includes: obtaining channel state information of a described object; and feeding back the obtained channel state information to a base station in a comb manner. A method for channel estimation includes: receiving channel state information that is reported by a terminal in a comb manner; and determining, according to the channel state information that is reported in the comb manner, channel state information corresponding to a described object that does not report channel state information.