Sidelink Resource Assignment and Collision Avoidance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication systems, particularly in sidelink direct communications, packet collisions occur when user equipment (UEs) autonomously select the same resources without detecting each other's presence, leading to interference and communication losses, especially in 'hidden terminal' scenarios where UEs are out of range during initial resource selection but later move into overlapping coverage.
Innovation Solution
A method where a victim UE detects overlapping resources and broadcasts an indication to other UEs, causing them to stop transmission on those resources and reselect new ones, excluding the overlapping ones to prevent packet collisions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If UEs autonomously select resources for sidelink transmission, then resource allocation flexibility is improved, but packet collisions occur when multiple UEs select the same resources
Solution Approach 1:
The patent implements a feedback mechanism where UEs monitor the sidelink channel for resource selections made by other UEs and provide feedback information indicating resource conflicts. This allows the system to maintain autonomous resource selection while using feedback to identify and resolve collisions, thus preserving flexibility while improving reliability.
Solution Approach 2:
The patent introduces an intermediary resource allocation entity (such as a base station or scheduling entity) that receives resource selection information from UEs, detects potential collisions, and provides adjusted resource allocations. This intermediary resolves the contradiction by maintaining UE autonomy in resource selection while adding a coordination layer that prevents collisions.
2Device complexity
If UEs do not detect each other's presence during initial resource selection, then device complexity is reduced, but hidden terminal scenarios cause packet collisions when UEs later move into overlapping coverage
Solution Approach 1:
The patent applies preliminary action by having UEs perform initial resource selection without complex detection mechanisms, then subsequently monitor for collision indicators and adjust resource selections. This separates the resource selection phase from the collision resolution phase, maintaining low complexity during initial selection while ensuring reliability through later collision detection and resolution.
Solution Approach 2:
The patent uses feedback mechanisms where UEs monitor for indicators of resource conflicts after initial resource selection and provide feedback to adjust their resource allocations. This allows the system to maintain simple initial resource selection while using feedback-driven adjustments to resolve hidden terminal scenarios and prevent packet collisions.
3Reliability
If UEs continuously monitor for overlapping resources, then packet collision avoidance is improved, but energy consumption increases
Solution Approach 1:
The patent implements periodic monitoring where UEs check for overlapping resources at specific intervals rather than continuously. This reduces energy consumption by keeping the monitoring mechanism inactive between periodic checks, while still maintaining adequate collision avoidance capability through regular resource conflict detection.
Solution Approach 2:
The patent enables UEs to self-adjust their monitoring activity based on their transmission status and detected collision risk. When UEs are not transmitting or when no conflicts are detected, they reduce or suspend monitoring activities, consuming minimal energy. Monitoring is activated or intensified only when necessary for collision avoidance.
Data Source
AI summary
Certain aspects of the present disclosure provide techniques for resource block assignment and packet collision avoidance in sidelink communications. A method that may be performed by a first user equipment (UE) generally includes determining at least a first set of resources for a second UE overlaps at least a second set of resources for a third UE. The method generally includes broadcasting an indication of overlapping resources to at least the second UE and the third UE.