Sidelink Feedback Repetition Scheduling to Avoid PSFCH Collisions

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Solution Overview

Problem

Existing wireless communication systems face challenges in efficiently managing sidelink feedback channel repetitions, leading to collisions and interference in sidelink communications, particularly in NR and LTE networks.

Innovation Solution

The proposed solution involves selecting PSSCH resources for sidelink transmissions such that they do not collide with PSFCH resources based on a defined repetition factor, thereby avoiding collisions and optimizing sidelink feedback channel operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If PSFCH repetitions are implemented to improve feedback reliability, then feedback reliability is improved, but resource collision and interference increase

Engineering Contradiction:
Improvefeedback reliabilityVSAvoidresource collision and interference
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the PSFCH resources into multiple sets (first set and second set) with different repetition factors. By dividing the feedback channel resources into distinct segments that can be independently configured, the system can allocate resources to avoid collisions while maintaining repetition for reliability. This segmentation allows simultaneous support for both feedback reliability and collision avoidance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces dynamic configuration where a UE can be configured with different repetition factors for different PSFCH resources based on channel conditions and traffic requirements. This dynamic adjustment allows the system to optimize between repetition (for reliability) and resource collision avoidance in real-time, resolving the contradiction between these two requirements.

Inventive Principle:
Principle #15Dynamics

2Productivity

If multiple PSSCH transmissions are scheduled to improve productivity, then productivity is improved, but PSFCH resource collision increases

Engineering Contradiction:
Improvesidelink transmission efficiencyVSAvoidPSFCH resource collision
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by assigning different repetition factors to different PSFCH resources based on their specific characteristics and usage patterns. Instead of uniform treatment, each PSFCH resource is configured with appropriate repetition based on local conditions (such as associated PSSCH transmission characteristics), enabling multiple PSSCH transmissions to proceed efficiently while avoiding PSFCH collisions through localized optimization.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent implements preliminary action by having the UE select and configure PSFCH resources with appropriate repetition factors before actual transmissions occur. The UE determines the repetition factor in advance based on configured parameters and channel conditions, allowing multiple PSSCH transmissions to be scheduled without causing PSFCH collisions. This advance preparation enables efficient scheduling while preventing resource conflicts.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4295521B1Sidelink feedback channel repetitions
Publication Date: 2025.12.17 QUALCOMM INC
  • EP4295521B1 patent drawingFigure 1
  • EP4295521B1 patent drawingFigure 2
  • EP4295521B1 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 send, to a second UE, a first physical sidelink shared channel (PSSCH) transmission. The first UE may select, for a second PSSCH transmission, a PSSCH resource for which a corresponding physical sidelink feedback channel (PSFCH) resource does not collide with one of a plurality of PSFCH transmissions in accordance with a repetition factor associated with the first PSSCH transmission. The first UE may send, to the second UE, the second PSSCH transmission via the PSSCH resource. Numerous other aspects are described.