Sidelink Grant Reallocation After Shared-Spectrum LBT Failure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing sidelink communication systems face challenges in managing listen-before-talk (LBT) failures on shared spectrum, leading to inefficiencies and interference in device-to-device communication.
Innovation Solution
A Slidelink transmission method that employs resource selection procedures and inter-UE coordination to handle LBT failures, allowing wireless devices to dynamically adjust transmission resources and mitigate interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If devices perform listen-before-talk (LBT) procedures on shared spectrum, then interference mitigation is improved, but transmission reliability deteriorates due to LBT failures
Solution Approach 1:
The system performs preliminary actions by pre-selecting multiple candidate transmission resources and pre-coordinating with neighboring UEs before actual transmission. When LBT fails on the primary resource, the UE can immediately switch to a pre-identified alternative resource without additional LBT procedures, thus maintaining reliability while still benefiting from initial interference mitigation efforts.
Solution Approach 2:
The patent implements beforehand cushioning by establishing inter-UE coordination mechanisms that identify and reserve alternative transmission resources in advance. This creates a safety buffer against LBT failures, ensuring that if the primary transmission resource becomes unavailable due to LBT failure, the UE already has a backup resource ready, thus cushioning the impact on transmission reliability.
2Reliability
If devices dynamically adjust transmission resources to handle LBT failures, then transmission reliability is improved, but device complexity increases
Solution Approach 1:
The system implements feedback mechanisms where UEs exchange information about their LBT outcomes and transmission status with neighboring UEs. This feedback enables coordinated resource selection and allows devices to adapt their transmission strategies based on real-time channel conditions and neighboring UE states, improving reliability through collective intelligence rather than individual complexity.
Solution Approach 2:
The patent introduces an intermediary coordination mechanism where UEs communicate through standardized signaling protocols to negotiate and coordinate resource usage. This intermediary layer simplifies individual device complexity by handling the complex coordination logic through established communication interfaces, rather than requiring each device to implement complex peer-to-peer negotiation algorithms.
3Productivity
If multiple candidate resources are pre-selected for sidelink transmission, then transmission efficiency is improved during LBT failure recovery, but resource utilization deteriorates due to potential resource waste
Solution Approach 1:
The system applies dynamics by making resource selection adaptive rather than static. UEs dynamically select from pre-identified candidate resources based on real-time LBT outcomes and channel conditions. The resource selection strategy adjusts according to the number of LBT failures and current spectrum availability, optimizing the balance between transmission efficiency and resource utilization rather than always using multiple candidate resources.
Solution Approach 2:
The patent implements parameter changes by adjusting transmission parameters such as power level, modulation scheme, and resource selection based on LBT failure patterns and channel conditions. When LBT failures occur, the system changes transmission parameters to utilize alternative resources more efficiently, rather than simply switching to pre-selected resources regardless of conditions, thus reducing resource waste while maintaining efficiency.
Data Source
AI summary
A wireless device receives a radio resource control (RRC) message indicating a first resource pool of a sidelink (SL) communication. The wireless device determines, from a candidate resource set in the first resource pool, a SL grant indicating resources for one or more SL transmissions of the SL communication. The wireless device receives, by a medium access control (MAC) layer from a physical layer of the wireless device, an indication of SL listen before talk (LBT) failure of a first resource of the resources indicated in the SL grant. Based on the indication, the wireless device selects, for the first resource, a second resource from the first resource pool excluding resources associated with SL LBT failure. The wireless device transmits, via the second resource, the one or more SL transmissions of the SL communication.