PSFCH Resource Allocation in Unlicensed Sidelink Interlaces

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Solution Overview

Problem

In sidelink communication systems using unlicensed spectrum, there is a lack of clear methods for determining resources for the sidelink feedback channel, which affects the balance between the requirements of the unlicensed spectrum and the demand for sidelink feedback information transmission.

Innovation Solution

A method for sidelink transmission that involves determining transmission resources for the Physical Sidelink Feedback Channel (PSFCH) using a common interlace and dedicated Resource Blocks (RBs), considering the interlace structure in the unlicensed spectrum to balance resource allocation and feedback demands.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional resource allocation methods are used for PSFCH in unlicensed spectrum, then the implementation is simple, but the resource allocation does not meet the requirements of unlicensed spectrum and feedback transmission demands

Engineering Contradiction:
Improveadaptability to unlicensed spectrum requirementsVSAvoidresource determination complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The resource pool is segmented into multiple interlaces, where each interlace contains non-contiguous resource blocks. This segmentation allows the PSFCH to be allocated specific interlaces that satisfy unlicensed spectrum requirements while maintaining clear resource boundaries and manageable allocation complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different interlaces are assigned to different PSFCH transmission scenarios based on local requirements. The resource allocation adapts to specific unlicensed spectrum conditions by selecting appropriate interlaces for specific feedback transmissions, rather than using a uniform allocation scheme.

Inventive Principle:
Principle #3Local quality

2Reliability

If more resources are allocated to PSFCH to meet feedback demands, then feedback transmission reliability improves, but resource waste in unlicensed spectrum increases

Engineering Contradiction:
Improvesidelink feedback transmission reliabilityVSAvoidspectrum resource waste
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The PSFCH resource allocation is made dynamic by allowing the receiving terminal to select from multiple candidate interlaces based on channel conditions and feedback requirements. This dynamic selection ensures sufficient resources are allocated for reliable feedback transmission while avoiding permanent allocation of excess resources that would be wasted in the shared unlicensed spectrum.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The resource allocation parameters (interlace selection, resource block indices) are changed adaptively based on transmission needs and channel conditions. This allows the system to allocate exactly the right amount of resources needed for reliable feedback without over-provisioning and wasting spectrum resources.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4704485A1Method for sidelink transmission and terminal device
Publication Date: 2026.03.04 GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP LTD
  • EP4704485A1 patent drawingFigure 1~2
  • EP4704485A1 patent drawingFigure 3~5
  • EP4704485A1 patent drawingFigure 6~8

AI summary

Provided are a method for sidelink transmission and a terminal device. The method comprises: a first terminal device determining transmission resources of a first PSFCH, wherein the transmission resource of the first PSFCH comprises one or more of the following: a common comb tooth occupied by the first PSFCH; and a dedicated RB occupied by the first PSFCH. On the basis of the present application, the first terminal device can determine transmission resources of a PSFCH in an unlicensed spectrum on the basis of a comb tooth structure. Thus, according to the present application, when determining a resource of a sidelink feedback channel, the comb tooth structure involved in the unlicensed spectrum is considered, thereby considering both the requirements for the unlicensed spectrum and the requirements for transmission of sidelink feedback information.