Sidelink Resource Mapping for Cross-COT PSFCH in Unlicensed NR

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Solution Overview

Problem

There is a need to improve Sidelink (SL) communication procedures in 5G/New Radio (NR) environments, particularly in unlicensed spectrum, to enhance resource selection for PSFCH Cross-COT transmissions, maintain COT, handle PSFCH retransmissions, and support SL HARQ reporting, while ensuring efficient use of the unlicensed spectrum without impacting licensed spectrum performance.

Innovation Solution

A user equipment (UE) device performs SL communication procedures by selecting resources on unlicensed spectrum bands between 4.1 GHz and 7.125 GHz, using configured or preconfigured SL BWPs, and employing SL physical channels like PSBCH, PSCCH, PSSCH, and PSFCH, with COT configurations and resource selection patterns to optimize SL transmissions, including PSFCH cross-COT and retransmissions, and HARQ-ACK reporting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If resources are selected from unlicensed spectrum for SL transmissions, then spectrum utilization is improved, but channel access delay increases due to LBT requirements

Engineering Contradiction:

Improvespectrum utilizationVSAvoidchannel access delay

Core Design Contradiction:

Quantity of substanceVSLoss of time

Solution Approach 1:

The network configures SL resource pools in advance with pre-defined time-frequency resources for sidelink transmissions. This preliminary configuration allows UEs to quickly access pre-approved resources without performing full LBT procedures, thereby reducing channel access delay while maintaining efficient unlicensed spectrum utilization

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent dynamically adjusts LBT parameters such as contention window size and backoff counters based on channel conditions and traffic priorities. By changing these parameters adaptively, the system optimizes the balance between spectrum utilization and channel access delay, allowing critical SL transmissions to access resources faster while maintaining fair spectrum sharing

Inventive Principle:

Principle #35Parameter changes

2Object-affected harmful factors

If SL resource pools are configured with restricted time resources, then interference with licensed spectrum is reduced, but resource allocation flexibility decreases

Engineering Contradiction:

Improveinterference with licensed spectrumVSAvoidresource allocation flexibility

Core Design Contradiction:

Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The unlicensed spectrum resource pool is segmented into multiple time slots and frequency sub-channels, with different portions allocated for SL transmissions during specific time windows. This segmentation allows the system to restrict SL resources to specific time-frequency regions, reducing interference with licensed spectrum operations while maintaining flexibility through selective activation of different resource segments based on traffic demands

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The SL resource pool configuration is made dynamic, allowing the network to adjust the time-frequency allocation patterns in real-time based on channel conditions, traffic load, and interference levels. This dynamic reconfiguration enables the system to adapt resource allocation flexibility while maintaining restrictions that prevent harmful interference to licensed spectrum

Inventive Principle:

Principle #15Dynamics

3Loss of time

If PSFCH transmissions are performed cross-COT, then HARQ feedback timing is improved, but power consumption increases

Engineering Contradiction:

ImproveHARQ feedback timingVSAvoidpower consumption

Core Design Contradiction:

Loss of timeVSUse of energy by moving object

Solution Approach 1:

The patent combines multiple PSFCH transmissions into a single cross-COT opportunity when possible. By merging HARQ feedback for multiple SL transmissions into one consolidated PSFCH transmission within the same COT, the system improves HARQ feedback timing efficiency while reducing the total number of separate transmissions, thereby lowering overall power consumption

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS20260059601A1Terminal, System, and Method for Mapping Resources in Sidelink Communication Procedures

Publication Date: 2026.02.26 APPLE INC

AI summary

A terminal may include a processor configured to obtain a sidelink (SL) monitoring information indicating resources selected for a bandwidth that includes a portion of an unlicensed spectrum. The processor may be configured to perform a resource selection procedure in accordance with the SL monitoring information. The terminal may include a transmitter coupled to the processor and configured to transmit the SL transmission, in which resources are selected in accordance with the source selection procedure.