Uplink Timing Advance Pre-compensation for Non-terrestrial Networks
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Solution Overview
Problem
In non-terrestrial networks, terminals face challenges with unintended artificial delays due to propagation delay differences, requiring additional procedures for base stations to obtain timing advance information, which increases signaling overhead and reduces scheduling efficiency.
Innovation Solution
A method for uplink signal transmission in non-terrestrial networks where terminals receive and use terminal-specific timing information, calculated based on satellite ephemeris and location data, to adjust uplink timing, reducing random access delays and signaling overhead by implicitly reporting pre-compensated timing advance information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the base station obtains timing advance information from the terminal through additional procedures, then the uplink timing accuracy is improved, but the signaling overhead increases and scheduling efficiency decreases
Solution Approach 1:
The terminal calculates and applies its own timing advance based on pre-compensated TA information derived from satellite ephemeris and location data, eliminating the need for base station to request and process TA information from the terminal. This self-service approach reduces signaling overhead while maintaining timing accuracy.
Solution Approach 2:
The terminal performs pre-compensation of timing advance information before uplink transmission based on satellite ephemeris and location data. This preliminary action allows the terminal to autonomously determine the appropriate timing without requiring additional procedures from the base station, thereby reducing signaling overhead.
2Reliability
If terminals apply terminal-specific offset to uplink transmission timing, then the propagation delay compensation is improved, but the complexity of timing management increases
Solution Approach 1:
Each terminal independently calculates its own timing advance offset using satellite ephemeris information and location data, eliminating the need for centralized timing management by the base station. This self-service approach maintains reliable propagation delay compensation while reducing timing management complexity through distributed autonomous calculation.
Solution Approach 2:
The terminal adjusts its uplink transmission timing by applying a calculated offset based on satellite ephemeris and location parameters. This parameter change approach allows each terminal to compensate for its specific propagation delay independently, maintaining reliability without requiring complex centralized timing management.
3Measurement precision
If the base station defines and adds new resources and channels for TA information exchange, then the timing advance acquisition is improved, but the network complexity increases
Solution Approach 1:
The terminal autonomously acquires timing advance information by calculating pre-compensated TA based on satellite ephemeris and location data, eliminating the need for base station to define new resources and channels for TA information exchange. This self-service approach improves timing advance acquisition while avoiding increased network complexity.
Solution Approach 2:
The timing advance acquisition function is extracted from the base station and transferred to the terminal. The terminal independently calculates and applies timing advance based on satellite ephemeris and location data, eliminating the need for base station to define new resources and channels, thereby avoiding increased network complexity.
Data Source
AI summary
A method of a terminal may comprise: receiving, from a base station, information on Timing Advance (TA) groups, which are divided into groups, each having a specific unit size, based on a range for TAs occurring within a cell, and information on group-specific scheduling offsets mapped to the TA groups; calculating a pre-compensated TA based on satellite ephemeris information of the base station and location information of the terminal; identifying a group-specific scheduling offset mapped to a TA group corresponding to the pre-compensated TA; and transmitting a first uplink signal including a preamble to the base station using an uplink timing adjusted based on the group-specific scheduling offset.