Relay Node Channel Status Feedback Threshold Mechanism

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Solution Overview

Problem

Relay nodes in wireless communication systems face challenges in efficiently transmitting uplink signals and feedback information due to limited subframe availability and resource overhead, particularly because they do not need to frequently report channel status changes like user equipment, leading to potential errors and degraded performance.

Innovation Solution

A method and apparatus for a relay node to receive downlink backhaul subframe information from a base station, including timing indication for uplink subframes, and measure channel status using downlink reference signals, transmitting differential values as feedback only when changes exceed a threshold, thereby optimizing uplink signal transmission and reducing resource overhead.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If relay nodes transmit feedback information repeatedly with a predetermined cycle like conventional user equipment, then channel status can be maintained, but resource overhead increases and communication performance degrades

Engineering Contradiction:
Improvechannel status maintenanceVSAvoidresource overhead
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent implements aperiodic feedback transmission where relay nodes only send feedback information when channel status changes exceed a threshold, rather than transmitting periodically at fixed intervals. This selective periodic action reduces resource overhead while maintaining reliable channel status information at the base station.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent changes the transmission parameter from fixed periodic cycles to variable trigger-based intervals. Feedback transmission is activated only when channel status variation exceeds a predetermined threshold, dynamically adjusting the feedback frequency based on actual channel conditions rather than following a rigid periodic schedule.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If relay nodes frequently report channel status changes, then communication performance can be maintained, but resource overhead increases

Engineering Contradiction:
Improvecommunication performanceVSAvoidresource overhead
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent implements a threshold-based feedback mechanism where relay nodes monitor channel status changes and only transmit feedback when variations exceed a predetermined threshold. This selective feedback approach ensures the base station receives meaningful channel status updates without being overwhelmed by redundant information, maintaining communication performance while reducing resource consumption.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

Instead of transmitting feedback for every channel status change (excessive action), the patent applies partial action by only reporting when changes exceed a significant threshold. This partial feedback strategy maintains adequate communication performance by providing sufficient channel status information without the resource overhead of reporting every minor variation.

Inventive Principle:
Principle #16Partial or excessive action

3Quantity of substance

If relay nodes do not transmit feedback information, then resource overhead is reduced, but base station cannot perform link adaptation

Engineering Contradiction:
Improveresource overheadVSAvoidlink adaptation capability
Core Design Contradiction:
Quantity of substanceVSAdaptability or versatility

Solution Approach 1:

The patent establishes a threshold-based feedback system where relay nodes transmit channel status information when changes exceed a predetermined level. This ensures the base station receives sufficient feedback to perform link adaptation and maintain optimal communication parameters, while avoiding resource overhead from transmitting unnecessary feedback information for minor channel variations.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2398160B1Method for transmitting an uplink signal and feedback information, and relay apparatus using the method
Publication Date: 2018.11.21 LG ELECTRONICS INC
  • EP2398160B1 patent drawingFigure 1
  • EP2398160B1 patent drawingFigure 2
  • EP2398160B1 patent drawingFigure 3

AI summary

The invention relates to a method for transmitting an uplink signal and feedback information of a relay, and to a relay apparatus using the method. The relay can receive information, constituting a downlink backhaul subframe and an uplink backhaul subframe from a base station. The relay can transmit an uplink signal via the relevant uplink backhaul subframe on the basis of the received information constituting the uplink backhaul frame. Further, the relay can receive a downlink reference signal from the base station, measure the status of a channel, and transmit the status of the channel in values, in various formats and in various points in time and cycles, to the base station.