LBT Type Based PUSCH Transmission in Unlicensed Bands
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication systems face inefficiencies in unlicensed bands due to the need for channel sensing before transmission, which can lead to interference and limited flexibility in beamforming with multiple antenna elements, especially in mmWave bands where installing transceivers for each antenna element is costly and inefficient.
Innovation Solution
A method for user equipment (UE) to perform operations based on Listen Before Talk (LBT) types in unlicensed bands, including random back-off, no back-off, and no LBT, allowing for flexible PUSCH transmission by acquiring LBT type and PUSCH starting position information from a base station, enabling efficient use of unlicensed bands and reducing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If transceivers are installed for each antenna element to enable independent beamforming control, then beamforming flexibility and coverage are improved, but device cost and complexity increase significantly
Solution Approach 1:
The patent combines multiple antenna elements into antenna ports, where one antenna port can represent one or more antenna elements. This merging approach allows the system to achieve beamforming functionality without requiring a separate transceiver for each antenna element, thereby reducing device complexity while maintaining adaptability through virtual antenna port configurations.
Solution Approach 2:
The patent enables a single antenna port to serve multiple functions by representing different sets of antenna elements for different beamforming operations. This multi-functionality allows the same physical infrastructure to support various beamforming patterns and directions without requiring additional transceivers, resolving the contradiction between flexibility and complexity.
2Reliability
If channel sensing (LBT) is performed before transmission in unlicensed bands to reduce interference, then spectral efficiency and fair coexistence are improved, but transmission delay and loss of time increase
Solution Approach 1:
The patent performs Listen Before Talk (LBT) channel sensing as a preliminary action before actual data transmission. By checking channel availability in advance and only proceeding when the channel is clear, the system ensures reliable interference-free transmission while minimizing delays through efficient backoff mechanisms and early channel assessment.
Solution Approach 2:
The patent implements dynamic LBT operations where the sensing and transmission timing are adjusted based on real-time channel conditions. This dynamic approach allows the system to adapt transmission schedules to current spectral availability, reducing unnecessary waiting time when channels are clear while maintaining reliability when interference is detected.
3Productivity
If multiple PUSCH starting position candidates are supported to enable flexible transmission scheduling, then spectral efficiency and resource utilization are improved, but device complexity and processing requirements increase
Solution Approach 1:
The patent segments the uplink transmission timeline into multiple possible starting positions for PUSCH transmissions. By defining discrete candidate starting positions (e.g., first candidate, second candidate, third candidate) rather than allowing continuous scheduling, the system achieves flexible resource utilization while keeping the processing complexity manageable through a有限的 set of predefined options.
Solution Approach 2:
The patent changes the time parameter of PUSCH starting positions to achieve flexible scheduling. By varying the starting position candidates in the time domain and selecting appropriate candidates based on LBT outcomes and channel conditions, the system improves spectral efficiency without requiring complex spatial or frequency domain adjustments.
Data Source
AI summary
The present invention provides a method, performed by a user equipment (UE), for performing an action according to the type of listen before talk (LBT) in an unlicensed band, the method comprising the steps of: obtaining, from a base station, information about an LBT type and information about a physical uplink shared channel (PUSCH) starting position through an uplink (UL) grant; performing, on the basis of the obtained LBT type, an action according to the LBT type; and transmitting a PUSCH on the basis of the information about the PUSCH starting position after performing the action according to the LBT type, wherein the information about the PUSCH starting position indicates the position of any one of a plurality of PUSCH starting position candidates.