Multi-Carrier LBT Channel Time Sharing in Unlicensed Bands
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless access systems face inefficiencies in uplink data transmission in unlicensed bands, particularly in multiple carrier environments, where existing listen before talk (LBT) methods do not effectively utilize channel time and resources, leading to suboptimal throughput for both base stations and user equipment.
Innovation Solution
A method for performing uplink LBT in multiple carriers, where the base station shares remaining channel time with user equipment after downlink transmissions, optimizing resource allocation and increasing throughput by aligning LBT operations across carriers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional uplink LBT methods are used in unlicensed bands, then channel access is achieved, but channel time is not effectively utilized and throughput is suboptimal
Solution Approach 1:
The base station performs downlink LBT and acquires channel access in advance, then shares the remaining channel time with user equipment for uplink transmission without requiring UE to perform separate LBT, thereby preliminarily securing channel access for both directions
Solution Approach 2:
The patent enables continuous data transmission by allowing uplink transmission to immediately follow downlink transmission within the same channel access period, eliminating idle gaps and maintaining continuous useful action on the channel
2Productivity
If separate LBT operations are performed on multiple carriers, then channel access control is maintained, but LBT complexity increases and resource utilization decreases
Solution Approach 1:
The patent merges LBT operations across multiple carriers by allowing the base station to perform downlink LBT on one carrier and share the acquired channel access with user equipment for uplink transmission on the same or different carriers, eliminating redundant separate LBT operations
Solution Approach 2:
The base station's downlink channel access grant is made universal across multiple carriers, allowing the same channel access permission to be utilized for both downlink and uplink transmissions on different carriers without requiring carrier-specific LBT procedures
Data Source
Figure 1
Figure 2(a)~2(b)
Figure 3
AI summary
The present invention relates to a wireless access system supporting an unlicensed band, and to methods for performing uplink listen before talk (LBT) on multiple carriers, and a device supporting the same. According to one embodiment of the present invention, a method by which a terminal performs LBT in a wireless access system supporting an unlicensed band and multiple carriers can comprise the steps of: receiving, from a base station, each of uplink grants for scheduling uplink channels on two or more component carriers (CCs); randomly selecting a first CC on which a first LBT is to be performed from among the two or more CCs; performing the first LBT on the selected first CC: and performing a second LBT on the remaining CCs among the two or more CCs, wherein the first LBT can be a random back-off-based LBT for performing a random back-off by a random back-off counter value, and the second LBT can be a channel sensing-based LBT for sensing a channel during a predetermined time interval before uplink transmission.