PSSCH Feedback Delay Reduction via PSFCH Occasion Selection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing communication methods involving Physical Sidelink Share Channel (PSSCH) face increased feedback delay and monitoring overhead due to large time intervals between PSSCH and PSFCH occasions, necessitating improved HARQ information feedback mechanisms.

Innovation Solution

The method involves selecting a subset of N PSFCH occasions from M available occasions, where N is determined based on a time threshold, ensuring the interval between PSFCH occasions and PSSCH is less than or equal to the threshold, thereby reducing feedback delay and resource overhead.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If HARQ information is fed back on PSFCH occasions with large time interval from PSSCH, then the channel access opportunity is increased, but the feedback delay and monitoring overhead increase

Engineering Contradiction:
ImproveHARQ feedback reliabilityVSAvoidfeedback delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent segments the PSFCH occasions into multiple candidate occasions and selects only those that satisfy the time interval threshold condition. This segmentation approach allows the system to divide the feedback mechanism into valid and invalid occasions, thereby reducing feedback delay while maintaining reliability through selective occasion usage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent dynamically determines the number of valid PSFCH occasions based on the time interval threshold. The terminal adapts the feedback mechanism by adjusting which occasions are considered valid, creating a dynamic feedback system that responds to timing conditions rather than using a static approach.

Inventive Principle:
Principle #15Dynamics

2Reliability

If HARQ information is fed back on PSFCH occasions with large time interval from PSSCH, then the channel access opportunity is increased, but the monitoring overhead increases

Engineering Contradiction:
ImproveHARQ feedback reliabilityVSAvoidmonitoring overhead
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the PSFCH occasions into multiple candidate occasions and selects only those that satisfy the time interval threshold condition. This segmentation approach allows the system to divide the feedback mechanism into valid and invalid occasions, thereby reducing monitoring overhead while maintaining reliability through selective occasion usage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies partial action by using only a subset of available PSFCH occasions rather than all occasions. By selecting only those occasions that meet the time interval criterion, the system performs partial feedback operations, reducing monitoring overhead while maintaining sufficient feedback reliability.

Inventive Principle:
Principle #16Partial or excessive action

3Reliability

If all M PSFCH occasions are used for HARQ feedback, then the feedback opportunity is maximized, but the resource consumption increases

Engineering Contradiction:
Improvefeedback opportunityVSAvoidresource consumption
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent extracts only the necessary PSFCH occasions that satisfy the time interval threshold from the complete set of M occasions. This extraction approach removes unnecessary feedback opportunities that would consume resources, keeping only the essential occasions that provide adequate feedback reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies partial action by using only a subset of available PSFCH occasions rather than all occasions. By selecting only those occasions that meet the time interval criterion, the system performs partial feedback operations, reducing resource consumption while maintaining sufficient feedback opportunity.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP4694228A1Communication method, apparatus and device, and storage medium
Publication Date: 2026.02.11 BEIJING XIAOMI MOBILE SOFTWARE CO LTD
  • EP4694228A1 patent drawingFigure 1A~1B
  • EP4694228A1 patent drawingFigure 2A~2B
  • EP4694228A1 patent drawingFigure 3A~4A

AI summary

The present disclosure relates to a communication method, apparatus and device, and storage medium. The method comprises: a first user equipment transmitting a physical sidelink shared channel (PSSCH) to a second user equipment; determining N physical sidelink feedback channel (PSFCH) occasions for the PSSCH, wherein N is less than or equal to M, the value of M is the number of PSFCH occasions mapped by the PSSCH, and N and M are positive integers; and on the N PSFCH occasions, receiving and decoding hybrid automatic repeat request (HARQ) information transmitted by the second user equipment, and on an (N+1)th PSFCH occasion to an Mth PSFCH occasion, not receiving or decoding the HARQ information. Thus, the effect of reducing a PSSCH feedback delay is achieved.