Sidelink HARQ Feedback for UE Cooperation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current UE cooperation solutions in wireless communication systems do not efficiently exploit sidelink communication capabilities for HARQ mechanisms, leading to increased complexity and resource inefficiency, particularly in scenarios like V2X communications where latency and resource conflicts are prevalent.

Innovation Solution

Implementing UE cooperation schemes that utilize sidelink HARQ feedback to enable CUEs to cooperate by retransmitting selected code block groups or outer-coded data, allowing for distributed cooperation without base station scheduling, even if a CUE does not fully decode the data block, thereby reducing resource usage and improving efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If UE cooperation with sidelink communications is implemented for HARQ feedback, then reliability and throughput are enhanced, but network communication complexity increases

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidnetwork communication complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the HARQ feedback mechanism into multiple components: initial transmission from base station, sidelink feedback from target UE to cooperating UE, and selective retransmission. This segmentation allows distributed HARQ operations while managing complexity through modular feedback handling.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements partial action by allowing cooperating UEs to participate in HARQ feedback only when they have successfully decoded the transport block. Not all UEs are required to participate in sidelink HARQ, reducing overall system complexity while maintaining reliability benefits where applicable.

Inventive Principle:
Principle #16Partial or excessive action

2Productivity

If joint UE reception using sidelink communications is implemented, then system throughput and coverage are increased, but HARQ signaling complexity increases

Engineering Contradiction:
Improvesystem throughputVSAvoidHARQ signaling complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent extracts the HARQ feedback function from centralized base station control and distributes it to target UEs and cooperating UEs via sidelink communications. This extraction enables throughput enhancement through diverse reception paths while managing signaling complexity through standardized feedback formats.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent implements feedback mechanisms where target UEs send HARQ acknowledgments to cooperating UEs via sidelink, enabling selective retransmission. This feedback loop improves throughput by allowing cooperative UEs to assist only when beneficial, while the standardized feedback protocol manages signaling complexity.

Inventive Principle:
Principle #23Feedback

3Loss of energy

If sidelink HARQ feedback is implemented for UE cooperation, then resource usage is reduced, but implementation complexity increases

Engineering Contradiction:
Improveresource usage efficiencyVSAvoidimplementation complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent implements preliminary action by establishing sidelink HARQ feedback capabilities and resource allocations in advance through base station configuration. This preliminary setup reduces resource usage during actual data transmission while managing implementation complexity through pre-negotiated parameters and reserved resources.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3921964B1Systems and methods for user equipment cooperation with sidelink HARQ feedback
Publication Date: 2024.04.03 HUAWEI TECH CO LTD
  • EP3921964B1 patent drawingFigure 1
  • EP3921964B1 patent drawingFigure 2~3
  • EP3921964B1 patent drawingFigure 4

AI summary

Methods and devices utilizing sidelink transmission between user equipment (UEs) for HARQ retransmission are provided. The sidelinkHARQ retransmissions include data from the initial transmission or an outer coded version thereof. HARQ feedback from the targeted receiver of the initial transmission may identify code block groups and/or individual code blocks the target receiver did not successfully decode. A UE that has not successfully decoded an entire transport block, may still cooperate in HARQ retransmission for the targeted receiver of the transport block by retransmitting at least a subset of the code block groups that it was able to successfully decode for the transport block.