Triggered HARQ Codebook for Timely Sidelink Feedback

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Solution Overview

Problem

Existing wireless communication systems face challenges in efficiently managing hybrid automatic repeat request (HARQ) feedback for sidelink communications, particularly in scenarios with carrier aggregation, leading to inefficient network resource utilization and user experience degradation due to delayed or cancelled transmissions.

Innovation Solution

Implementing a hybrid automatic repeat request (HARQ) codebook design that includes triggered HARQ feedback, allowing for one-shot, semi-static, or dynamic feedback schemes, triggered by a signaling mechanism to improve channel access and resource utilization for sidelink UEs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional HARQ feedback mechanisms are used in sidelink communications with carrier aggregation, then system compatibility is maintained, but network resource utilization deteriorates and feedback timeliness decreases

Engineering Contradiction:
ImproveHARQ feedback timelinessVSAvoidnetwork resource utilization
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent implements dynamic HARQ feedback mechanisms where the feedback timing and resource allocation are adaptively adjusted based on channel conditions and traffic requirements. The system dynamically selects between different feedback modes (Type-1, Type-2, Type-3 codebooks) and adjusts the timing of feedback transmission to optimize both timeliness and resource utilization in sidelink carrier aggregation scenarios.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes key HARQ feedback parameters including the timing offset between data reception and feedback transmission, the resource allocation for feedback channels, and the codebook type selection. These parameter changes enable the system to adapt to varying channel conditions and traffic patterns, improving feedback timeliness while maintaining efficient resource utilization in carrier aggregation environments.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If HARQ feedback transmissions are increased to improve reliability, then feedback timeliness improves, but network resource consumption increases

Engineering Contradiction:
ImproveHARQ feedback deliveryVSAvoidnetwork resource consumption
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent applies partial action by selectively transmitting HARQ feedback only when necessary based on the type of service and channel conditions. For example, Type-3 codebooks are used for specific scenarios where only certain carriers need feedback, reducing overall feedback transmissions while maintaining reliability for critical communications in sidelink carrier aggregation.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent implements feedback mechanisms where the receiving UE provides HARQ acknowledgments to the transmitting UE, enabling adaptive retransmissions. The system uses feedback information to adjust transmission parameters, power levels, and resource allocation, optimizing the balance between feedback delivery reliability and network resource consumption in sidelink scenarios.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If multiple HARQ codebooks are supported for carrier aggregation, then feedback accuracy improves, but device complexity increases

Engineering Contradiction:
ImproveHARQ feedback accuracyVSAvoidcodebook management complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the HARQ feedback into multiple codebooks (Type-1, Type-2, Type-3) where each codebook serves specific carriers or traffic types in the carrier aggregation configuration. This segmentation allows the system to maintain high feedback accuracy for each segment while managing overall complexity through standardized processing procedures for each codebook type in sidelink communications.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent creates universal codebook structures that can handle multiple carriers and traffic types through standardized formats and procedures. The Type-3 codebook, for example, provides a universal mechanism for providing additional HARQ feedback information across multiple carriers without requiring separate handling for each carrier, reducing device complexity while maintaining feedback accuracy in carrier aggregation scenarios.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4264858B1Hybrid automatic repeat request codebook design for a sidelink
Publication Date: 2026.04.15 QUALCOMM INC
  • EP4264858B1 patent drawingFigure 1
  • EP4264858B1 patent drawingFigure 2
  • EP4264858B1 patent drawingFigure 3

AI summary

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a first user equipment (UE) may receive, from a second UE via a sidelink interface, a triggering signal associated with triggering hybrid automatic repeat request (HARQ) feedback for a sidelink. The UE may transmit, to the second UE and based at least in part on the triggering signal, HARQ feedback associated with the second UE. Numerous other aspects are provided.