HARQ Feedback Mechanism for Multicast Communication Reliability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In multicast communication for NR V2X, the existing HARQ feedback mechanism struggles to distinguish between UEs that have successfully decoded data (ACK) and those that have failed to decode (DTX), leading to inaccurate determination of data retransmission needs and poor communication reliability.

Innovation Solution

A HARQ feedback method that monitors the feedback information of other UEs in a group upon failure to decode SCI, determines whether to send a HARQ-NACK or data request information, and sends it on a preset resource, thereby improving communication reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If multiple UEs use the same feedback resource to send feedback information, then resource utilization is improved, but the ability to distinguish between ACK and DTX states deteriorates

Engineering Contradiction:
Improvefeedback resource utilizationVSAvoidfeedback state discrimination accuracy
Core Design Contradiction:
Quantity of substanceVSMeasurement precision

Solution Approach 1:

The feedback resource is segmented into multiple independent feedback channels, where each channel corresponds to a specific UE. This allows the receiving UE to distinguish which UE sent which feedback type (ACK or DTX), resolving the ambiguity caused by shared feedback resources while maintaining efficient resource utilization through structured allocation.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If the existing feedback mechanism is used, then implementation simplicity is improved, but communication reliability deteriorates due to inability to determine retransmission needs

Engineering Contradiction:
Improvefeedback mechanism complexityVSAvoiddata transmission reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The invention introduces an enhanced feedback mechanism where receiving UEs monitor feedback channels to detect both ACK and DTX states. The receiving UE uses this feedback information to make informed retransmission decisions, creating a closed-loop feedback system that significantly improves communication reliability while maintaining reasonable implementation complexity through standardized procedures.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3910835B1HARQ feedback method and device for multicast communication, storage medium, and terminal
Publication Date: 2025.03.05 BEIJING SPREADTRUM HI TECH COMM TECH CO LTD
  • EP3910835B1 patent drawingFigure 1
  • EP3910835B1 patent drawingFigure 2~3
  • EP3910835B1 patent drawingFigure 4~5

AI summary

An HARQ feedback method and device for multicast communication, a storage medium, and a terminal. The method comprises: in response to a failure to encode sidelink control information, listening to HARQ feedback information of other UEs in a group; determining, according to the HARQ feedback information of the other UEs in the group, whether or not HARQ-NACK feedback information or data request information needs to be sent; and if so, sending the HARQ-NACK feedback information or the data request information over a preset resource. The solution provided by the present invention can effectively improve communication reliability.