Sidelink Channel Access on Unlicensed Spectrum With Coordinated LBT
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Solution Overview
Problem
In sidelink transmission systems operating on unlicensed spectra, terminals face challenges in determining how to transmit data efficiently while avoiding interference and ensuring fair access to shared spectrum resources.
Innovation Solution
A terminal device determines available transmission resources based on a channel access procedure, such as Listen Before Talk (LBT), to decide whether to use those resources for sidelink transmission, thereby optimizing data transmission on unlicensed spectra.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If terminals perform LBT on unlicensed spectrum for sidelink transmission, then fair access to shared spectrum resources is ensured, but transmission efficiency and data throughput are reduced due to repeated channel access attempts
Solution Approach 1:
The patent applies preliminary action by having the first terminal perform LBT and successfully access the channel before initiating the sidelink transmission procedure. The first terminal determines a first time resource for transmission based on the LBT result, and only after this preliminary channel access does the second terminal need to perform LBT. This sequence ensures fair spectrum access while reducing the number of repeated LBT attempts that would otherwise occur if both terminals performed LBT independently without coordination.
2Ease of manufacture
If terminals independently perform LBT for channel access, then spectrum sharing is simplified, but interference between terminals increases and channel utilization is reduced
Solution Approach 1:
The patent introduces an intermediary mechanism where the first terminal's LBT result and determined time resource serve as coordination information for the second terminal. The second terminal uses this intermediary information to determine whether to perform LBT and when to perform it, rather than independently attempting channel access. This intermediary coordination reduces interference between terminals while maintaining relatively simple individual LBT procedures.
3Reliability
If LBT is performed before each transmission opportunity, then collision avoidance is improved, but time consumption and transmission delay increase
Solution Approach 1:
The patent applies preliminary action by having the first terminal complete its LBT and determine the first time resource before the second terminal needs to transmit. This preliminary determination allows the second terminal to perform LBT only when necessary, rather than before every possible transmission opportunity. The coordination information from the first terminal enables this optimized timing, reducing overall time consumption while maintaining collision avoidance through the coordinated LBT procedure.
Data Source
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AI summary
Embodiments of the present application provide a wireless communication method and device. A terminal device may determine, on the basis of a result of a channel access process, whether to use an available transmission resource to perform sidelink transmission, so that the terminal device may use an unlicensed spectrum to perform sidelink transmission. The wireless communication method comprises that: a terminal device determines K available transmission resources; for the i-th available transmission resource in the K available transmission resources, the terminal device determines, according to the result of the channel access process, whether to use the i-th available transmission resource to perform sidelink transmission, wherein i and K are positive integers, and 1 ≤ i ≤ K.