Sidelink Feedback Resource Indexing for V2X Acknowledgements

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Solution Overview

Problem

Existing wireless communication systems face challenges in efficiently managing feedback resources for transport blocks in V2X sidelink communications, particularly in 4G and 5G networks, leading to suboptimal performance and resource utilization.

Innovation Solution

A method for a wireless device to receive configuration parameters for feedback resources, identify a second wireless device through sidelink control information, and transmit acknowledgments using an index-based feedback mechanism that incorporates device identities and modulo operations on available resources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If feedback resources are allocated for each transport block in V2X sidelink communications, then acknowledgement reliability is improved, but resource overhead and system complexity increase

Engineering Contradiction:
Improveacknowledgement reliabilityVSAvoidfeedback resource management complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple feedback resources into a shared pool that multiple wireless devices can utilize. Instead of allocating dedicated feedback resources to each transport block, the system creates a merged resource pool where devices select feedback resources based on their identities and transport block indices, reducing overall system complexity while maintaining acknowledgement reliability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The feedback resources are designed to serve multiple purposes and multiple devices simultaneously. A single feedback resource can be used by different wireless devices for different transport blocks, making the feedback mechanism universal rather than dedicated. This multi-functionality reduces resource overhead and simplifies management while preserving reliability through proper resource selection based on device and transport block identities.

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

2Measurement precision

If dedicated feedback resources are assigned to each transport block, then acknowledgement accuracy is improved, but resource overhead increases

Engineering Contradiction:
Improveacknowledgement accuracyVSAvoidfeedback resource overhead
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent segments the feedback resource selection process into multiple components: device identity-based selection, transport block index-based selection, and modulo operation-based final determination. This segmentation allows the system to maintain acknowledgement accuracy through multi-factor differentiation while reducing overall resource overhead by sharing the feedback resource pool among multiple devices and transport blocks.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system changes the parameters used for feedback resource identification from dedicated per-transport-block allocation to a combination of device identity, transport block index, and modulo operation results. This parameter transformation enables multiple devices to share feedback resources while maintaining the ability to accurately identify and process individual acknowledgements, thereby reducing resource overhead without sacrificing accuracy.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If feedback resources are shared among multiple devices, then resource efficiency is improved, but resource conflict and interference increase

Engineering Contradiction:
Improveresource efficiencyVSAvoidresource conflict
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent introduces asymmetry into the feedback resource selection process by using device-specific identities and transport block-specific indices in the resource selection formula. This asymmetric selection criterion ensures that different devices and different transport blocks map to different feedback resources with high probability, reducing conflicts and interference while allowing efficient sharing of the feedback resource pool among multiple devices.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The modulo operation serves as an intermediary mechanism that transforms device identities and transport block indices into feedback resource indices. This intermediary function systematically distributes feedback resource assignments, reducing direct conflicts while maintaining resource efficiency. The modulo operation acts as a mediator that balances the competing requirements of resource sharing and conflict avoidance.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4503499B1Feedback resource
Publication Date: 2026.04.22 TOYOTA JIDOSHA KK
  • EP4503499B1 patent drawingFigure 1A~1B
  • EP4503499B1 patent drawingFigure 2A~2B
  • EP4503499B1 patent drawingFigure 3

AI summary

A first wireless device receives, from a base station, one or more radio resource control messages comprising configuration parameters of feedback resources. The first wireless device receives, from a second wireless device, sidelink control information comprising an identity, ID, of the second wireless device. The first wireless device receives, from the second wireless device, a transport block. The first wireless device transmits, to the second wireless device, an acknowledgement for the transport block via a feedback resource, among the feedback resources, having an index. The index is based on: the ID of the second wireless device, an ID of the first wireless device, and a modulo operation performed on a quantity of the feedback resources.