User Terminal SUL Carrier Scheduling Without CIF Overhead
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Solution Overview
Problem
Future radio communication systems face challenges in controlling uplink signal transmission on Supplemental UpLink (SUL) carriers due to the absence of downlink signals, leading to inefficiencies in scheduling and increased payload capacity of downlink control information.
Innovation Solution
A cross-carrier scheduling scheme is employed without using the conventional carrier indicator field (CIF) and with limited configuration targets, utilizing downlink control information specific to SUL carriers, and controlling uplink transmission power, timing, and channel types to manage SUL scheduling effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional cross-carrier scheduling with CIF is used for SUL carriers, then UL transmission can be controlled, but DCI payload capacity increases and scheduling efficiency deteriorates
Solution Approach 1:
The patent extracts and removes the Carrier Indicator Field (CIF) from the DCI structure for SUL carrier scheduling. By taking out the CIF, the patent eliminates the need for explicit carrier identification in the DCI, thereby reducing the DCI payload capacity while maintaining reliable UL transmission control through alternative mechanisms such as search space configuration and control resource set association.
2Productivity
If SUL carrier is used for UL transmission only, then bandwidth utilization improves, but scheduling control becomes difficult
Solution Approach 1:
The patent introduces an intermediary control mechanism where the gNodeB configures search spaces and control resource sets in association with SUL carriers. This intermediary configuration system enables the gNodeB to indirectly control UL transmission scheduling on SUL carriers without requiring direct downlink signals on the SUL carrier itself, thus maintaining ease of operation while preserving bandwidth utilization benefits.
Solution Approach 2:
The patent applies preliminary action by configuring search spaces and control resource sets in advance before UL transmission occurs. The gNodeB pre-configures the UE with the necessary control information structures, enabling the UE to autonomously determine and execute UL scheduling decisions based on pre-established control resource associations, thereby simplifying real-time scheduling control.
3Object-affected harmful factors
If DL signal is not transmitted on SUL carrier, then interference is reduced, but control information transmission becomes inefficient
Solution Approach 1:
The patent transitions from a traditional downlink-centric control transmission model to an uplink-oriented control information transmission model. Instead of transmitting control information for SUL carriers through downlink signals on the SUL carrier itself, the patent uses uplink control information transmitted on other carriers (non-SUL carriers) to control UL transmission on the SUL carrier. This dimensional shift from downlink to uplink control transmission resolves the interference issue while maintaining control efficiency.
Data Source
Figure 1A~1B
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AI summary
To appropriately configure an SUL (Supplemental UpLink) carrier when the SUL carrier is used, a user terminal according to one aspect of the present invention is a user terminal that performs communication by using a first carrier on which at least DL transmission is performed and a second carrier on which only UL transmission is performed. The user terminal includes a receiving section that receives certain downlink control information transmitted from the first carrier, and a control section that controls UL signal transmission on the second carrier, based on the certain downlink control information. The certain downlink control information is one of a downlink control information transmitted on a certain condition without a carrier indicator field (CIF), and a downlink control information including a CIF configured independently of a CIF of downlink control information used for notification of at least DL allocation.