V2X Resource Selection for HARQ Retransmissions

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Solution Overview

Problem

In V2X communication, existing technologies face challenges in selecting multiple resources for blind or feedback-based retransmissions, particularly in balancing delay budget, resource collision, and signaling overhead, especially when configuring a threshold transmission number.

Innovation Solution

A method and device for selecting resources in a terminal device, where resources with time-domain offsets below a threshold offset are identified and communicated through sidelink control information, supporting up to 32 Hybrid Automatic Repeat Request (HARQ) retransmissions by indicating continuous frequency resources within a resource selection window.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple resources are selected for blind or feedback-based retransmissions, then transmission reliability is improved, but signaling overhead increases

Engineering Contradiction:

Improvetransmission reliabilityVSAvoidsignaling overhead

Core Design Contradiction:

ReliabilityVSLoss of information

Solution Approach 1:

The patent segments the resource selection process into two distinct phases: first selecting resources for initial transmission, then separately selecting resources for retransmission based on feedback or blind retransmission mechanisms. This segmentation allows the signaling to only indicate the initial resource selection rather than all possible retransmission resources, reducing signaling overhead while maintaining reliability through separate retransmission resource allocation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies preliminary action by pre-configuring retransmission resources or pre-determining resource selection criteria before actual transmission occurs. The receiver pre-preares acknowledgment mechanisms or the transmitter pre-establishes retransmission resource pools, so that when retransmission is needed, resources are already allocated without requiring additional signaling to indicate every possible retransmission resource.

Inventive Principle:

Principle #10Preliminary action

2Loss of time

If resources are selected considering delay budget, then transmission timeliness is improved, but resource collision risk increases

Engineering Contradiction:

Improvedelay budgetVSAvoidresource collision

Core Design Contradiction:

Loss of timeVSObject-affected harmful factors

Solution Approach 1:

The patent implements dynamic resource selection where the available resource pool and selection criteria are adjusted based on real-time conditions including delay requirements and collision detection. The system dynamically modifies resource allocation strategies based on feedback information, allowing flexible adaptation to changing network conditions while maintaining both timeliness and collision avoidance.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent employs feedback mechanisms where receivers provide acknowledgment information about resource usage and transmission success. This feedback enables transmitters to adjust their resource selection for retransmissions based on actual conditions, reducing collision risk by avoiding resources that have been identified as problematic while still meeting delay budget requirements.

Inventive Principle:

Principle #23Feedback

3Reliability

If threshold transmission number is configured for blind retransmission, then transmission reliability is improved, but resource selection complexity increases

Engineering Contradiction:

Improvetransmission reliabilityVSAvoidresource selection complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies partial action by implementing blind retransmission only up to a configured threshold number of times rather than attempting unlimited retransmissions. This partial approach to retransmission management simplifies the resource selection process by limiting the search space and computational complexity to a manageable threshold while still providing sufficient reliability for most communication scenarios.

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The patent utilizes parameter changes by adjusting the threshold transmission number and other retransmission parameters based on channel conditions, message importance, and network load. This dynamic parameter adjustment allows the system to optimize between reliability and complexity by increasing the threshold when reliability is critical and decreasing it when complexity should be minimized.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20220394678A1Method, device and computer readable medium for resource selection in v2x

Publication Date: 2022.12.08 NEC CORP

AI summary

Embodiments of the present disclosure relate to method, device and computer readable medium for resource selection in V2X. The method comprises selecting, at a first terminal device, resources in at least one resource selection window for transmissions of data from the first terminal device to a second terminal device. The method also comprises determining a first number N of continuous resources in a set of the selected resources that have time-domain offsets with respect to a reference resource below a threshold offset T. The method also comprises transmitting sidelink control information to the second terminal device. The sidelink control information indicates the N continuous resources in the set of the selected resources located in the at least one resource selection window. The selected resources comprise a plurality of frequency resources in a single slot.