Long PSFCH Resource Mapping for V2X HARQ Feedback

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Solution Overview

Problem

The existing static PSFCH format in NR sidelink communications is insufficient to accommodate various types of networking and can cause fragmentation and collision of retransmissions, lacking adaptability for different UE scenarios.

Innovation Solution

Implement a configurable 'long' PSFCH format that utilizes unused physical resource blocks from the PSCCH and PSSCH resource pool, allowing for adaptive resource mapping and indexing to accommodate multiple transport blocks, enhancing ACK/NACK messaging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a static PSFCH format is used in NR sidelink communications, then the system structure is simple, but it is insufficient to accommodate various types of networking and causes fragmentation and collision of retransmissions

Engineering Contradiction:
Improveadaptability to various networking typesVSAvoidPSFCH format complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent introduces a configurable PSFCH format that can dynamically switch between short and long formats based on the number of transport blocks. This dynamic adaptability allows the system to accommodate various networking types (unicast, groupcast, broadcast) without requiring a completely complex structure, as the format adjusts only when needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the parameter of PSFCH duration (short vs. long format) to adapt to different networking scenarios. By modifying this single parameter based on the number of transport blocks, the system achieves versatility across different networking types while maintaining structural simplicity when the short format suffices.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If a static PSFCH format is used, then the configuration is simple, but retransmission collisions occur due to insufficient resource allocation

Engineering Contradiction:
Improveretransmission reliabilityVSAvoidresource allocation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic resource allocation where the PSFCH format (short or long) is selected based on the number of transport blocks. This dynamic approach prevents retransmission collisions by ensuring sufficient resources are allocated when multiple transport blocks are present, while avoiding unnecessary complexity when a single transport block is transmitted.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention segments the PSFCH resources into short and long formats, with each segment optimized for specific scenarios. The short format handles simple cases efficiently, while the long format provides expanded resources for complex scenarios with multiple transport blocks, thereby preventing collisions without over-provisioning resources in all cases.

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If a long PSFCH format is implemented to accommodate multiple transport blocks, then adaptability improves, but resource overhead increases

Engineering Contradiction:
Improvesupport for multiple transport blocksVSAvoidresource block usage
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent employs dynamic format selection where the long PSFCH format is activated only when the number of transport blocks exceeds one. This dynamic approach provides the necessary adaptability to support multiple transport blocks while avoiding the resource overhead of using the long format universally, thus optimizing resource block usage.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the PSFCH duration parameter from short to long format based on the number of transport blocks. This parameter change enables support for multiple transport blocks only when necessary, preventing unnecessary resource consumption in scenarios where a single transport block is transmitted, thereby balancing adaptability with resource efficiency.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4165885B1Physical sidelink feedback channel (PSFCH) range extension with long psfch format
Publication Date: 2025.11.05 APPLE INC
  • EP4165885B1 patent drawingFigure 1~2
  • EP4165885B1 patent drawingFigure 3
  • EP4165885B1 patent drawingFigure 4

AI summary

Embodiments are presented herein of apparatuses, systems, and methods for performing vehicle-to-everything (V2X) sidelink communications with hybrid automatic repeat request (HARQ) feedback include using a new long physical sidelink feedback channel (PFSCH) format, i.e., PFSCH format 1, to assign feedback resources for various sidelink communication networks and environments where the existing or legacy sidelink feedback format, i.e., the short PFSCH format, referred to herein as PFSCH format 0, is insufficient to support effective acknowledgements (ACKs) and non-acknowledgements (NACKs) due to the limited nature of the format design.