Uplink Control Information Reporting in LAA Systems
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Solution Overview
Problem
Current wireless communication systems face limitations in flexibility and efficiency, particularly in uplink control information reporting for License-Assisted Access (LAA) transmissions, due to the unreliable nature of unlicensed spectrum and the need for listen-before-talk (LBT) protocols, which can lead to unpredictable and inefficient use of resources.
Innovation Solution
The system determines the type of uplink control information (UCI) to report and selects appropriate channels for transmission, prioritizing licensed cells over LAA cells when possible, and employs listen-before-talk protocols to ensure reliable transmission, while also considering simultaneous PUCCH and PUSCH configurations to optimize resource usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If LAA uplink transmissions are used to improve communication capacity and flexibility, then spectrum utilization is enhanced, but transmission reliability deteriorates due to the unreliable nature of unlicensed spectrum and LBT protocols
Solution Approach 1:
The system segments uplink transmissions by separating LAA cell transmissions from licensed cell transmissions. UCI reporting is directed to licensed cells while data transmissions can utilize LAA cells, dividing the communication function to maintain reliability for control information while preserving flexibility for data transmission.
Solution Approach 2:
Licensed cells serve as an intermediary for UCI reporting when LAA cells are unavailable or unreliable. The system uses licensed cells as a backup communication path for control information, ensuring reliable UCI delivery while still allowing LAA cells to be used for data transmission when conditions permit.
2Adaptability or versatility
If LBT protocols are implemented to ensure fair spectrum access, then spectrum sharing is improved, but transmission efficiency deteriorates due to unpredictable channel access
Solution Approach 1:
The system segments the communication function by directing time-sensitive UCI reporting to licensed cells with guaranteed access while allowing LAA cells to perform LBT for data transmissions. This separation ensures that control information delivery is not delayed by LBT procedures while data transmission still benefits from fair spectrum sharing.
Solution Approach 2:
Different quality requirements are applied to different transmission types: UCI reporting requires high reliability and low latency, so it uses licensed cells with deterministic access; data transmission can tolerate variable delay, so it uses LAA cells with LBT-based fair access. Each transmission type is routed to the appropriate cell type based on its quality requirements.
3Productivity
If UCI reporting is performed on LAA cells to maximize resource utilization, then resource efficiency is improved, but reporting reliability deteriorates due to channel access uncertainty
Solution Approach 1:
The system segments the reporting function by directing UCI reports to licensed cells rather than LAA cells. This separation ensures that control information reporting uses the reliable licensed spectrum while data transmission utilizes LAA spectrum, achieving both reliability for reporting and efficiency for data communication.
Solution Approach 2:
Instead of using LAA cells for UCI reporting to maximize resource utilization, the system inverts the approach by using licensed cells for reporting and reserving LAA cells primarily for data transmission. This inversion prioritizes reporting reliability while maintaining overall resource efficiency through appropriate cell selection.
Data Source
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AI summary
A user equipment (UE) for reporting uplink control information (UCI) when one or more Licensed-Assisted Access (LAA) serving cells are configured is described. The UE includes a processor and memory in electronic communication with the processor. Instructions stored in the memory are executable to determine if physical uplink shared channel (PUSCH) transmissions are scheduled on LAA serving cells and licensed cells. The instructions are also executable to determine a type of UCI to be reported. The instructions are further executable to determine a channel and cells to carry different UCI. The instructions are additionally executable to transmit the channel on the cells determined to carry UCI. The instructions are also executable to determine whether a LAA PUSCH is transmitted and UCI is multiplexed. The instructions are further executable to drop LAA PUSCH or transmit LAA PUSCH subject to listen-before-talk (LBT).