NTN Uplink Timing Offset K_offset for Long TA
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Solution Overview
Problem
In Non-Terrestrial Networks (NTNs), the existing timing relationship between downlink (DL) and uplink (UL) transmissions is not adequately enhanced to accommodate the long timing advance (TA) requirements, leading to potential scheduling disorders and interference issues.
Innovation Solution
The introduction of a new timing offset, K_offset, is proposed to enhance the UL transmission timing in NTNs. This offset is based on the UL numerology and is used to adjust the timing of UL HARQ-ACK on PUCCH, UL transmission on PUSCH, and CSI transmission on PUSCH, ensuring proper alignment with DL timing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the existing timing relationship between DL and UL transmissions is used in NTNs, then the terrestrial network baseline design is maintained, but the long timing advance requirements in NTNs cannot be accommodated, leading to scheduling disorders and interference issues
Solution Approach 1:
The patent introduces a new parameter K_offset that is specifically designed for NTN scenarios. This parameter modifies the timing relationship between DL and UL transmissions by adding an additional offset beyond the standard K1 and K2 values. The K_offset parameter is configured based on NTN-specific requirements, allowing the system to accommodate long timing advance requirements while maintaining proper scheduling reliability.
2Reliability
If a new timing offset K_offset is introduced to accommodate long TA requirements in NTNs, then scheduling reliability is improved, but the system complexity increases due to additional timing parameters
Solution Approach 1:
The K_offset parameter is pre-configured and provided to the UE through RRC signaling before actual UL transmissions occur. This preliminary configuration allows the UE to have all necessary timing information (K1, K2, and K_offset) available in advance, eliminating the need for complex real-time calculations and reducing runtime processing complexity despite the additional parameter.
3Measurement precision
If the UL transmission timing is adjusted using K_offset, then timing alignment accuracy is improved, but the processing overhead increases due to additional timing calculations
Solution Approach 1:
The UE autonomously calculates the UL transmission timing by combining the received DCI slot index n with the pre-configured parameters K1, K2, and K_offset using the formula: UL slot = n + K1 + K2 + K_offset. This self-service approach allows the UE to perform the timing calculation independently without requiring additional network coordination or complex processing, thereby achieving accurate timing alignment with minimal processing overhead.
Data Source
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AI summary
A user equipment (UE) includes one or more non-transitory computer-readable media containing computer-executable instructions embodied therein, and at least one processor coupled to the one or more non-transitory computer-readable media. The at least one processor configured to execute the computer-executable instructions to receive downlink control information (DCI) on a downlink (DL) channel of a non-terrestrial network (NTN), the DL channel reception ending in a first slot, and transmit an uplink (UL) transmission on a UL channel of the NTN in a second slot. The second slot is separate from the first slot by a timing offset, where a duration of the timing offset is dependent on a type of the UL transmission and a numerology of the UL transmission.