Uplink Channel Access with Capability-Based LBT Parameters
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Solution Overview
Problem
Existing wireless communication systems face fairness issues in channel access procedures due to differences in beamwidth flexibility between user equipment (UE) and base stations, leading to unfair interference detection and channel occupancy when performing listen-before-talk (LBT) procedures with varying beam directions.
Innovation Solution
The communication device adjusts its LBT parameters, such as beamwidth, energy detection threshold, and channel sensing time, based on its antenna capability and signaling from the base station to ensure fair channel access in unlicensed bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the base station uses narrow beamwidth for LBT procedure, then the base station can detect interference more precisely in its specific direction, but user equipment with restricted beamwidth cannot perform fair channel access due to hardware limitations
Solution Approach 1:
The invention changes the beamwidth parameter dynamically based on the transmitting entity type. Base stations can adjust their beamwidth for LBT procedures to optimize interference detection, while UEs operate with their hardware-constrained beamwidth. This parameter adaptation resolves the contradiction by allowing each entity to use appropriate beamwidth settings for their capabilities.
Solution Approach 2:
The invention applies different beamwidth characteristics to different entities (base station vs. UE) based on their local capabilities. Base stations with adjustable beamwidth use narrow beams for precise interference detection in specific directions, while UEs with restricted beamwidth operate with wider effective beam patterns. This local quality differentiation resolves the fairness issue.
2Adaptability or versatility
If the base station adjusts beamwidth flexibly to provide various services, then service diversity is improved, but fairness problems arise in channel access between base station and user equipment
Solution Approach 1:
The invention introduces parameter changes based on entity type and service requirements. Base stations can dynamically adjust beamwidth for different services while UEs operate with fixed beamwidth characteristics. The LBT procedure parameters are adapted to reflect these differences, ensuring fair channel access despite the base station's greater flexibility.
Solution Approach 2:
The invention makes the beamwidth parameter dynamic for base stations while static for UEs. Base stations can adjust their beamwidth dynamically to provide various services, and the LBT procedure adapts to these changes. This dynamic approach maintains service diversity while ensuring fairness through appropriate parameter adjustment.
3Productivity
If multiple uplink transmissions with different beam directions are scheduled closely, then resource utilization is improved, but the UE cannot perform LBT procedure for all transmissions due to restricted beamwidth and single-beam focusing capability
Solution Approach 1:
The invention segments the LBT procedure into separate operations for each beam direction or transmission group. When multiple uplink transmissions with different beam directions are scheduled, the UE performs LBT procedures separately for each transmission or group of transmissions that can share the same beam, rather than requiring simultaneous LBT for all transmissions. This segmentation makes the LBT procedure feasible while maintaining resource utilization.
Solution Approach 2:
The invention merges LBT procedures for multiple transmissions that share the same beam direction or spatial filter. When multiple uplink transmissions can be performed using the same beam, the UE performs a single LBT procedure that covers all these transmissions, reducing the operational burden while maintaining resource utilization efficiency.
4Reliability
If the UE performs LBT procedure with wider beamwidth to detect interference from all directions, then channel access fairness is improved, but the UE cannot focus its beam in a specific direction for uplink transmission
Solution Approach 1:
The invention changes the effective beamwidth parameter used for LBT procedures based on the UE's hardware capabilities and the specific transmission requirements. The UE performs LBT with an effective beamwidth that accounts for its restricted physical beamwidth, rather than assuming ideal wide-beam capability. This parameter adjustment ensures fair channel access assessment while maintaining the ability to focus beams for actual transmissions.
Solution Approach 2:
The invention introduces an intermediary relationship between the UE's physical beamwidth hardware limitation and the LBT procedure requirements. The effective beamwidth used for LBT calculations serves as an intermediary parameter that bridges the gap between hardware constraints and fairness requirements, allowing the UE to perform fair channel access assessment without sacrificing beam focusing capability.
Data Source
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AI summary
A device (190) for handling channel access procedure includes a storage device (210) and a processing circuit (200) coupled to the storage device (210) and configured to execute instructions stored in the storage device (210). The storage device (210) is configured for storing the instructions of receiving an indication for an uplink transmission (ULT); determining at least one parameter of the device (190) for a listen-before-talk procedure (CDLBT) according to a capability of the device (190) or a signaling from a base station; and performing the uplink transmission (ULT) according to the indication. A device for handling channel access procedure determines a first spatial domain filter for a first uplink transmission and a second spatial domain filter for a second uplink transmission.