Sidelink COT Maintenance During PSFCH Feedback Gaps

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Solution Overview

Problem

In sidelink communication, maintaining channel occupancy time (COT) is challenging due to gaps in transmission caused by scheduled physical sidelink feedback channel (PSFCH) instances when no feedback is available, leading to potential loss of COT and the need for further listen-before-talk procedures.

Innovation Solution

Implementing a COT maintenance signal with cyclic prefix extension during PSFCH instances to fill transmission gaps and maintain COT, using PSFCH resources that do not interfere with other UEs, and sharing signal parameters for synchronization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If PSFCH instances are scheduled during COT for feedback transmission, then feedback reliability is improved, but transmission gaps are created causing COT loss

Engineering Contradiction:

Improvefeedback reliabilityVSAvoidchannel occupancy time

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent applies continuity of useful action by introducing COT maintenance signals that are transmitted during PSFCH instances to fill transmission gaps. This ensures the channel remains actively occupied and prevents COT loss while maintaining feedback transmission functionality.

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The COT maintenance signal acts as an intermediary element that bridges the gap between feedback transmission requirements and continuous channel occupancy. It is transmitted during PSFCH instances to maintain COT without interfering with the primary feedback function.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Duration of action of stationary object

If COT maintenance signal is transmitted during PSFCH instances, then channel occupancy is maintained, but signal interference may occur with other UEs

Engineering Contradiction:

Improvechannel occupancy timeVSAvoidsignal interference

Core Design Contradiction:

Duration of action of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by allocating specific PSFCH resources dedicated to COT maintenance signals, separate from resources used by other UEs for feedback transmission. This localized resource allocation prevents interference while maintaining channel occupancy.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent segments the PSFCH resources into different functional categories, with specific resources allocated for COT maintenance signals and other resources for regular feedback transmission. This segmentation allows both functions to coexist without interference.

Inventive Principle:

Principle #1Segmentation

3Device complexity

If traditional PSFCH transmission is used without COT maintenance, then device complexity is reduced, but additional listen-before-talk procedures are required

Engineering Contradiction:

Improvetransmission protocol complexityVSAvoidchannel clearance time

Core Design Contradiction:

Device complexityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by proactively transmitting COT maintenance signals during PSFCH instances before the channel would naturally become idle. This prevents the need for subsequent listen-before-talk procedures, reducing time loss while maintaining manageable device complexity.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS12574960B2Maintaining channel occupancy time in sidelink communication

Publication Date: 2026.03.10 QUALCOMM INC

AI summary

Disclosed are techniques for performing wireless communication. In some aspects, a first user equipment (UE) may determine that one or more physical sidelink feedback channel (PSFCH) instances are scheduled during a channel occupancy time (COT) corresponding to a sidelink transmission by the first UE to a second UE. In some examples, the first UE may transmit a COT maintenance signal during the one or more PSFCH instances, wherein at least one PSFCH symbol in the COT maintenance signal has a cyclic prefix extension.