Supplemental Uplink Carrier Configuration via Downlink Control
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Solution Overview
Problem
In future radio communication systems, configuring a Supplemental UpLink (SUL) carrier that only performs UL transmission is challenging due to the absence of DL signals, making it difficult to detect and estimate path loss for SUL carriers.
Innovation Solution
A user terminal is designed to receive UL transmission command information from a carrier performing DL transmission and transmit a UL measurement signal to the SUL carrier, allowing path loss estimation and configuration of the SUL carrier based on this information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a SUL carrier is configured to perform only UL transmission, then uplink coverage is improved, but path loss estimation becomes difficult due to absence of DL signals
Solution Approach 1:
The patent introduces an intermediary mechanism where the eNB transmits UL transmission command information on the DL carrier to trigger UL measurement signal transmission on the SUL carrier. This intermediary signaling mechanism enables path loss estimation on SUL without requiring DL signals to be present on the SUL carrier itself, thus resolving the contradiction between uplink-only operation and path loss measurement capability
Solution Approach 2:
The eNB performs preliminary action by transmitting UL transmission command information before the UE transmits UL measurement signals on the SUL carrier. This preliminary triggering mechanism ensures that the UE knows when and how to transmit measurement signals, enabling path loss estimation to be performed in advance for proper SUL configuration
2Object-generated harmful factors
If DL signals are not transmitted on SUL carrier, then uplink interference is reduced, but configuration of SUL carrier to UE becomes difficult
Solution Approach 1:
The DL carrier serves as an intermediary channel for transmitting configuration information and UL transmission commands to the UE. This allows the SUL carrier to maintain its uplink-only function (reducing interference) while still enabling proper configuration through the intermediary DL carrier signaling mechanism
Solution Approach 2:
The patent segments the communication functions: DL carrier handles downlink transmission and control signaling, while SUL carrier handles uplink transmission only. This segmentation allows each carrier to optimize its function without requiring the SUL carrier to support both DL and UL, thus reducing interference while maintaining configurability through separate control channels
Data Source
AI summary
A terminal is disclosed communicating using a first carrier performing at least Downlink (DL) transmission and a second carrier performing only Uplink (UL) transmission. The terminal includes a receiver that receives an indication regarding a UL, the indication included in downlink control information (DCI) that is reported from the first carrier and a processor that transmits a UL signal using the UL based on the indication. In other aspects, a radio communication method, a base station, and a system are also disclosed.