Uplink Transmission in Unlicensed Bands via LBT Type Segmentation
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Solution Overview
Problem
Current wireless communication systems face challenges in efficiently managing uplink transmissions in unlicensed bands, particularly in the NR-U system, where flexible scheduling and channel access procedures are needed to support various service requirements.
Innovation Solution
The proposed method involves a new UL scheduling indication method that allows for flexible indication of the PUSCH transmission starting symbol within a slot, and introduces LBT type 3 as an additional channel access procedure. This method also considers the processing time of user equipment when configuring margins based on LBT types.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If LBT type 3 is introduced as an additional channel access procedure, then the flexibility and efficiency of uplink transmissions in unlicensed bands is improved, but the device complexity and scheduling indication method complexity increases
Solution Approach 1:
The patent segments the LBT procedure into three distinct types (LBT type 1 with random back-off, LBT type 2 without random back-off, and LBT type 3 without LBT), each applicable to different scheduling scenarios. This segmentation allows the system to manage complexity by selecting appropriate LBT types based on specific transmission conditions rather than implementing a single complex procedure.
Solution Approach 2:
The patent introduces dynamic scheduling indication where the base station can flexibly indicate different LBT types and PUSCH starting positions based on real-time channel conditions and traffic requirements. This dynamic approach enables the system to adapt to changing conditions and optimize transmission efficiency without requiring fixed complex procedures.
2Adaptability or versatility
If flexible scheduling of PUSCH starting position is implemented, then the adaptability to various service requirements is improved, but the measurement precision and timing accuracy requirements increase
Solution Approach 1:
The patent employs parameter changes by introducing a starting position indication field that can take multiple values corresponding to different OFDM symbol positions within a slot. The base station dynamically adjusts this parameter based on service requirements, allowing flexible scheduling while managing precision requirements through standardized indication mechanisms.
3Reliability
If margin configuration considering UE processing time is implemented, then the reliability of communication is improved, but the device complexity and configuration complexity increases
Solution Approach 1:
The patent applies preliminary action by having the base station configure margins in advance based on the indicated LBT type before the actual transmission occurs. This preliminary configuration ensures that sufficient time is allocated for UE processing, improving communication reliability without requiring complex real-time adjustments during transmission.
Data Source
AI summary
The present invention relates to a method for transmitting a Physical Uplink Shared Channel (PUSCH), performed by a user equipment (UE) in an unlicensed band, the method comprising: receiving downlink control information (DCI) including information on a listen before talk (LBT) type and information on a PUSCH start position from a base station; and transmitting the PUSCH on the basis of the information on the LBT type and the information on the PUSCH start position, wherein the LBT type is one of LBT type 1, LBT type 2, and LBT type 3, a random backoff-based LBT is performed in the LBT type 1, an LBT without a random backoff is performed in the LBT type 2, and an uplink is transmitted without LBT in LBT type 3.