NR V2X Mode 2 Resource Reselection for Collision Reduction
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Solution Overview
Problem
The existing methods for UE autonomous resource allocation in the NR V2X system, particularly in Mode 2, are inadequate for handling non-periodic data arrival and resource reservation, necessitating an improved mechanism to manage resource selection and reselection.
Innovation Solution
A method involving initial resource selection, followed by first and second resource reselections based on predefined conditions triggered by sidelink control signaling (SCI) from other UEs, with resource reannouncement and power adjustment to ensure UE autonomous resource allocation in Mode 2.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If UE autonomously selects resources based on sensing information in one sensing window, then resource allocation flexibility is improved, but resource collision probability increases
Solution Approach 1:
The UE performs resource reselection before the scheduled transmission time when resource reservation information is received, proactively avoiding future collisions rather than reacting after collision detection. This preliminary action allows the UE to select alternative resources in advance, reducing collision probability while maintaining allocation flexibility.
Solution Approach 2:
The system uses SCI (Sidelink Control Information) to provide feedback about reserved resources to other UEs. When a UE receives SCI indicating resource reservation, it feeds back this information to adjust its own resource selection, creating a feedback loop that reduces collisions while preserving autonomous allocation capabilities.
2Reliability
If UE performs resource reselection upon receiving SCI from other UEs, then resource collision is reduced, but signaling overhead increases
Solution Approach 1:
Each UE independently monitors SCI from other UEs and autonomously decides whether to perform resource reselection based on the received reservation information. This self-service approach eliminates the need for centralized coordination signaling, reducing overall signaling overhead while maintaining collision reduction through distributed decision-making.
Solution Approach 2:
The resource reselection is triggered proactively upon receiving SCI before actual resource usage, allowing UEs to preemptively avoid collisions. This preliminary detection and response mechanism reduces the need for collision resolution signaling that would be required if collisions actually occurred.
3Measurement precision
If multiple resource reselections are performed, then resource allocation accuracy is improved, but processing time increases
Solution Approach 1:
The system dynamically determines the number of resource reselection operations based on current channel conditions, traffic patterns, and timing constraints. Rather than performing a fixed number of reselections, the UE adapts its reselection behavior to balance accuracy improvement against processing time loss, optimizing performance for varying operational scenarios.
Solution Approach 2:
Resource reselection operations are performed in advance of the scheduled transmission time when possible, allowing multiple reselection iterations to complete before data transmission begins. This preliminary processing ensures accurate resource allocation without delaying actual data transmission, effectively decoupling processing time from transmission timing.
Data Source
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AI summary
The present disclosure relates to a pre-5G or 5G communication system to be provided for supporting higher data rates Beyond 4G communication system such as LTE. Embodiments of the present application provide a method and a device for resource allocation. The method includes: initiating initial resource selection for temporarily selecting resources for data to be transmitted; performing a first resource reselection after initial resource selection is initiated and before UE announces resources, and when a first SCI transmitted by other UE is received and a predefined condition for triggering resource reselection is met, wherein a resource reserved by other UE indicated in first SCI is at least one of resources temporarily selected by UE; transmitting PSCCH or PSSCH on first resource according to a result of first resource reselection, and announcing other resources except first resource through transmitted SCI.