Directional LBT for Multiplexed Beams in High-Frequency Bands
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Solution Overview
Problem
In high-frequency bands above 52.6 GHz, existing channel access procedures face significant path loss challenges, particularly in multiplexed transmission beams, where omnidirectional listen-before-talk (LBT) methods are inefficient due to directional interference and varying energy detection thresholds.
Innovation Solution
The implementation of directional listen-before-talk (D-LBT) with proper energy detection (ED) values, bandwidth configuration, and beam selection for multiplexed transmission beams to enhance channel occupancy time (COT) management, allowing for efficient channel access in high-frequency bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If omnidirectional listen-before-talk (LBT) methods are used in high-frequency bands, then channel access can be performed, but path loss is significant and efficiency is reduced due to directional interference
Solution Approach 1:
The patent applies local quality by transitioning from omnidirectional LBT to directional LBT (D-LBT), where the energy detection threshold and listening behavior are customized for specific beam directions. Each beam direction has its own LBT parameters adapted to the local interference characteristics, allowing the system to overcome path loss by concentrating transmission energy in specific directions while performing channel access independently for each direction.
2Productivity
If multiple transmission beams are multiplexed in an obtained COT, then channel access opportunities increase, but configuration complexity increases for ED values, bandwidth, and beam selection
Solution Approach 1:
The patent applies segmentation by dividing the channel access procedure into independent beam-level operations. Each transmission beam is configured with its own energy detection threshold, LBT bandwidth, and beam selection parameters. This allows multiple beams to be multiplexed within an obtained COT independently, increasing channel access opportunities while managing complexity through modular beam-specific configurations rather than monolithic system-wide configuration.
3Loss of energy
If directional beams are used to concentrate energy, then path loss is reduced, but interference with other devices in different directions may increase
Solution Approach 1:
The patent applies dynamics by making the LBT parameters adaptive rather than static. The energy detection threshold, bandwidth, and beam selection are dynamically adjusted based on the specific beam direction and observed interference conditions. This allows the system to concentrate energy in specific directions to overcome path loss while dynamically managing interference with other devices by adapting LBT behavior to current channel conditions in each direction.
Data Source
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AI summary
Disclosed is a method of transmitting an uplink signal by a user equipment in a wireless communication system. Specifically, the method includes performing listen-before-talk (LBT) based on at least one LBT beam, and transmitting the uplink signal through a plurality of transmission beams based on success of the LBT. The at least one LBT beam covers the plurality of transmission beams, and the plurality of transmission beams is multiplexed.