NR Sidelink PSFCH Resource Allocation in 1 MHz Unlicensed Bands

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Solution Overview

Problem

The increasing demand for larger communication capacities and the need for enhanced mobile broadband communication in wireless systems, particularly in unlicensed bands, poses challenges in efficiently managing channel bandwidths for sidelink feedback channels, especially in scenarios involving vehicle-to-everything (V2X) communications and next-generation radio access technologies like NR.

Innovation Solution

The proposed solution involves obtaining and transmitting hybrid automatic repeat request (HARQ) feedback information using a resource block set that includes both dedicated and common physical resource blocks within a 1 MHz bandwidth, optimizing channel occupancy and feedback mechanisms in unlicensed bands.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the channel bandwidth for PSFCH is increased to accommodate more RBs, then the feedback capacity is improved, but the channel occupancy time and latency increase

Engineering Contradiction:
Improvefeedback capacityVSAvoidlatency
Core Design Contradiction:
Quantity of substanceVSLoss of time

Solution Approach 1:

The patent divides the PSFCH resources into two separate channels: a first PSFCH channel for transmitting first feedback information and a second PSFCH channel for transmitting second feedback information. This segmentation allows each channel to be optimized independently for its specific feedback requirements, preventing the need to increase overall channel bandwidth and thus avoiding increased latency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a spatial dimension by using different frequency resources (first and second PSFCH channels) to transmit feedback information simultaneously. This allows the system to increase feedback capacity without increasing the time duration, as the two channels operate in parallel across different frequency dimensions.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Loss of time

If the channel bandwidth is limited to 1 MHz, then the channel occupancy is reduced, but the available RBs for feedback are insufficient

Engineering Contradiction:
Improvechannel occupancy timeVSAvoidavailable RBs
Core Design Contradiction:
Loss of timeVSQuantity of substance

Solution Approach 1:

The patent segments the feedback transmission across two separate PSFCH channels, each operating within the 1 MHz bandwidth limitation. This allows the system to maintain short channel occupancy time while still providing sufficient feedback capacity by distributing the feedback load across multiple channels rather than requiring a single wide channel.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent makes the PSFCH resources multi-functional by allowing both the first and second PSFCH channels to transmit feedback information within the same 1 MHz bandwidth constraint. This universal approach enables the limited bandwidth to serve multiple feedback transmission purposes simultaneously, maximizing the use of available RBs without increasing overall occupancy time.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If more RBs are allocated for PSFCH, then the feedback reliability is improved, but the channel efficiency decreases

Engineering Contradiction:
Improvefeedback reliabilityVSAvoidchannel efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent segments the feedback transmission into two separate channels with dedicated RBs for each. This segmentation ensures that each channel maintains sufficient RBs for reliable feedback transmission while avoiding the inefficiency of over-allocating RBs to a single channel. The first and second PSFCH channels independently manage their own reliability without compromising overall channel efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by optimizing each PSFCH channel independently with its own dedicated RBs, allowing each channel to have the precise amount of resources needed for its specific feedback transmission requirements. This prevents waste of channel resources and maintains high channel efficiency while ensuring reliable feedback for each channel.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4580280A1Method and device for transmitting NR sidelink in consideration of occupied channel bandwidth requirement in unlicensed band
Publication Date: 2025.07.02 LG ELECTRONICS INC
  • EP4580280A1 patent drawingFigure 1
  • EP4580280A1 patent drawingFigure 2
  • EP4580280A1 patent drawingFigure 3

AI summary

An operating method of a first device (100) in a wireless communication system is presented. The method may comprise the steps of: acquiring information related to a resource block (RB) set, the RB set including a physical sidelink feedback channel (PSFCH) resource, and the PSFCH resource including at least one dedicated physical resource block (PRB) and at least one common PRB, which are included in a bandwidth of 1 MHz; and transmitting, on the basis of the at least one dedicated PRB, hybrid automatic repeat request (HARQ) feedback information on the basis that the at least one dedicated PRB and the at least one common PRB are included in the bandwidth of 1 MHz.