Terminal DCI Layer Control for Multi-Antenna UL
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Solution Overview
Problem
Current Next-Generation Mobile Communication Systems, specifically in NR Rel-15, face challenges in appropriately controlling Uplink (UL) transmission using more than four antenna ports, which limits spectral efficiency and communication throughput.
Innovation Solution
A terminal is equipped with a receiving section to decode downlink control information (DCI) containing fields indicating the number of layers for physical uplink shared channel (PUSCH) transmission, and a control section that determines the number of layers per coherent group based on specific fields in the DCI.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If UL transmission using more than four antenna ports is implemented, then spectral efficiency is improved, but the control complexity for determining number of layers per antenna group increases
Solution Approach 1:
The patent segments the antenna ports into multiple coherent groups (first coherent group, second coherent group, etc.), each with its own number of layers. This segmentation allows the system to handle more than four antenna ports by dividing them into manageable groups, thereby achieving higher spectral efficiency while maintaining controllable complexity through structured organization.
Solution Approach 2:
The patent dynamically determines the number of layers for each coherent group based on DCI fields (precoding information field and/or rank indication field). This dynamic adaptation allows the system to optimize the layer configuration for each antenna group according to actual channel conditions, improving spectral efficiency while managing complexity through flexible, data-driven control rather than fixed configurations.
2Productivity
If transmission using a precoder for UL transmission using more than four antenna ports is implemented, then communication throughput is improved, but the complexity of determining number of layers for each antenna group increases
Solution Approach 1:
The patent introduces DCI fields (precoding information field and rank indication field) as intermediaries that carry control information about the number of layers for each coherent group. These fields act as mediators between the base station's transmission decisions and the terminal's execution, enabling the terminal to determine the correct layer configuration without complex local calculations, thus improving throughput while simplifying the determination process.
Solution Approach 2:
The patent implements a feedback mechanism where the base station provides control information via DCI fields indicating the number of layers for each coherent group. The terminal uses this feedback to correctly configure the precoder and transmit data. This feedback loop ensures that the terminal has accurate information about the intended transmission configuration, improving throughput while avoiding complexity at the terminal by offloading the decision-making to the base station.
Data Source
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AI summary
A terminal according to an aspect of the present disclosure includes a receiving section that receives downlink control information (DCI) including one or more fields indicating a number of layers for physical uplink shared channel transmission, and a control section that determines the number of layers per coherent group for the physical uplink shared channel transmission, based on a specific field included in the DCI. According to an aspect of the present disclosure, UL transmission using more than four antenna ports can be appropriately controlled.