Sidelink Cyclic Prefix Extension for Autonomous LBT Compliance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In New Radio operating on an unlicensed frequency band, user equipment (UE) lacks a feasible method to independently determine a cyclic prefix extension (CPE) length for sidelink transmissions without assistance from a base station, leading to potential LBT failures and unreliable data transmission.
Innovation Solution
A method and apparatus for a first terminal to determine a CPE starting position based on transmission type information, including channel access procedures and shared channel occupancy, ensuring timely and reliable sidelink service transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If the UE transmits data through autonomous scheduling in sidelink, then the UE can perform independent transmission, but the UE cannot determine CPE length without base station assistance, leading to LBT failures
Solution Approach 1:
The UE autonomously determines its own CPE length by autonomously selecting a value from a preconfigured set of CPE lengths, without requiring base station assistance. This self-service mechanism enables the UE to independently make transmission decisions while ensuring LBT compliance, thereby resolving the contradiction between autonomous scheduling and transmission reliability.
2Ease of operation
If the UE uses preconfigured CPE lengths for autonomous transmission, then the UE can independently determine CPE length, but the transmission may not optimally satisfy gap requirements of 16 us or 25 us
Solution Approach 1:
The UE autonomously selects from multiple preconfigured CPE length values, allowing dynamic parameter adjustment based on transmission conditions. This enables the UE to change the CPE length parameter to optimally satisfy different gap requirements (16 us or 25 us) while maintaining ease of independent operation.
3Reliability
If the base station indicates CPE length for uplink transmission, then the transmission can satisfy gap requirements, but the UE cannot independently determine CPE for sidelink transmissions
Solution Approach 1:
The UE autonomously determines CPE length for sidelink transmissions by selecting from preconfigured values, eliminating the need for base station indication. This self-service approach enables independent determination capability while maintaining the ability to satisfy gap requirements through proper configuration.
Data Source
AI summary
A method for determining a cyclic prefix extension (CPE) includes: according to transmission type information that a first transmission meets, determining a CPE starting position corresponding to a target transmission resource for the first transmission. The transmission type information includes at least one of the following: belonging to a transmission after a first channel access type; belonging to a transmission after a second channel access type; there being no available shared channel occupancy information; there being one piece of available shared channel occupancy information; there being at least two pieces of available shared channel occupancy information; or belonging to a continuous multi-slot transmission.