FDD Uplink Band Mode Switching for Synchronization
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Solution Overview
Problem
When a UL band of FDD is used for both DL and UL in a time division manner, there is a possibility of radio communication not being favorably performed in the UL band, due to delayed DL transmission timing and potential synchronization issues of UL reception timings between the base station and terminal devices.
Innovation Solution
The base station switches the operation mode of the UL band between a first mode, where it is used solely for UL, and a second mode, where it is used for both DL and UL in a time division manner, by adjusting UL transmission timings and reporting timing advance commands to terminal devices, ensuring synchronization and optimal communication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a UL band of FDD is used for both DL and UL in a time division manner, then radio resource utilization is improved, but DL transmission timing is delayed and UL reception synchronization deteriorates
Solution Approach 1:
The UL band operation is segmented into two distinct modes: a first mode for UL-only operation and a second mode for time-division DL/UL operation. The base station segments the operation timeline by switching between these modes, allowing radio resources to be efficiently utilized when DL traffic is high while maintaining synchronization reliability when switching to UL-only mode
Solution Approach 2:
The base station dynamically switches the operation mode of the UL band between the first mode (UL-only) and the second mode (time-division DL/UL) based on traffic conditions. This dynamic adaptation allows the system to optimize radio resource utilization during high DL traffic periods while ensuring UL reception synchronization is maintained during UL-only periods
2Adaptability or versatility
If the UL band is used for both DL and UL in a time division manner, then flexibility in resource allocation is improved, but transmission timing adjustment complexity increases
Solution Approach 1:
The system employs dynamic mode switching between a first operation mode (UL-only) and a second operation mode (time-division DL/UL). The base station adjusts transmission timings by reporting different timing advance commands depending on the current mode, providing flexible resource allocation while managing complexity through standardized timing adjustment mechanisms
Solution Approach 2:
The base station changes operational parameters by switching between two distinct operation modes for the UL band. In the first mode, the band operates exclusively for UL; in the second mode, it operates for both DL and UL in time division. This parameter change approach enables flexible resource allocation without requiring complex real-time adjustments within each mode
Data Source
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AI summary
[Object] To enable radio communication to be performed more favorably in a UL band of FDD when the UL band is used for both DL and UL in a time division manner. [Solution] There is provided a device including: a switching unit configured to switch an operation mode of an uplink band of FDD between a first mode in which the uplink band is used for uplink and a second mode in which the uplink band is used for both downlink and uplink in a time division manner; and a control unit configured to give an instruction on a first timing advance on the basis of a downlink reception timing in a downlink band of FDD corresponding to the uplink band and an instruction on a second timing advance on the basis of a downlink reception timing in the uplink band.