Two-Stage Timing Advance for Non-Terrestrial Networks
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Solution Overview
Problem
The existing Timing Advance (TA) configuration in wireless communication systems, designed for terrestrial communications, is inadequate for Non-Terrestrial Networks (NTN) due to increased propagation delays, leading to synchronization issues and interference in uplink transmissions.
Innovation Solution
A two-stage TA adjustment method is introduced, where the first stage provides coarse synchronization and the second stage offers fine-grained adjustments, using Q1 and Q2 candidate adjustments with distinct minimum step-sizes related to sub-carrier spacing, to ensure accurate timing alignment in NTN communications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional Timing Advance configuration is used in NTN communications, then uplink transmission timing can be adjusted for terrestrial scenarios, but synchronization accuracy deteriorates due to large propagation delays from satellites
Solution Approach 1:
The timing adjustment is divided into two independent stages: first timing adjustment based on satellite ephemeris information to compensate for large propagation delays, and second timing adjustment for fine-tuning synchronization. This segmentation allows each stage to operate with appropriate precision for its specific function.
Solution Approach 2:
The first timing adjustment is performed in advance using pre-acquired satellite ephemeris information before actual uplink transmission begins. This preliminary compensation for propagation delays establishes a foundation for subsequent fine-tuning operations.
2Adaptability or versatility
If a single timing adjustment mechanism is used, then system complexity is reduced, but the ability to adapt to different propagation delay scenarios deteriorates
Solution Approach 1:
The timing adjustment mechanism is segmented into two distinct adjustment processes with different purposes and precision requirements, allowing the system to adapt to NTN propagation characteristics while maintaining manageable complexity through clear functional separation.
Solution Approach 2:
Different adjustment mechanisms are applied to different aspects of timing control: coarse adjustment handles large propagation delay variations specific to NTN, while fine adjustment handles residual synchronization errors. Each part has optimized properties for its specific function.
3Measurement precision
If fine-grained timing adjustments are made, then synchronization accuracy is improved, but signaling overhead and processing complexity increase
Solution Approach 1:
The timing adjustment process is segmented into coarse and fine stages, with the fine adjustment building upon the foundation established by coarse adjustment. This reduces the range and complexity of fine-tuning operations while achieving high synchronization accuracy.
Solution Approach 2:
Coarse timing adjustment is performed in advance to compensate for major propagation delay effects, thereby reducing the magnitude of adjustments needed in subsequent fine-tuning operations and simplifying the fine adjustment process.
Data Source
AI summary
The present disclosure provides a method and a device in a communication node for wireless communications. The communication node in the present disclosure first receives first information, then receives second information, and then transmits a first radio signal; wherein the first information is used to determine a first transmission timing adjustment, the second information is used to determine a second transmission timing adjustment, and a start time for a transmission of the first radio signal is related to the first transmission timing adjustment and the second transmission timing adjustment; a minimum step-size size corresponding to the first transmission timing adjustment is not equal to a minimum step-size size corresponding to the second transmission timing adjustment; the first information, the second information and the first radio signal are all transmitted through an air interface. The disclosure can support large-delay-transmission and reduce overhead for configuring signaling of Time Advance (TA).