Multi RTT Positioning Timing Advance for NTN Location Verification
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Solution Overview
Problem
Current network-based UE location verification in Non-Terrestrial Networks (NTN) using Physical Cell Identity is not highly accurate due to large cell sizes spanning multiple countries, necessitating improved methods for precise location determination.
Innovation Solution
The method involves a User Equipment (UE) determining multiple uplink measurement occasions and generating timing advance reports based on Global Navigation Satellite System (GNSS) location data and satellite ephemeris, which are then transmitted to the satellite, allowing for more accurate UE location verification through multi-round trip time (RTT) positioning techniques, eliminating the need for traditional Positioning Reference Signal measurements and minimizing timing errors caused by satellite movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional Physical Cell Identity based location verification is used in NTN, then the system can perform basic location verification, but the accuracy is low due to large cell sizes spanning multiple countries
Solution Approach 1:
The patent replaces the traditional network-based Physical Cell Identity positioning method with a GNSS-based positioning approach. The UE uses GNSS to determine its location and calculates timing advance values based on its known position and the satellite's ephemeris data, eliminating the need for complex network-based measurement and verification procedures.
Solution Approach 2:
The UE performs self-positioning by using its own GNSS-based location data and the satellite's ephemeris to calculate timing advance values. The UE independently determines measurement occasions and transmits timing advance reports without requiring extensive network coordination or verification procedures.
2Measurement precision
If multi-RTT positioning with GNSS and ephemeris data is used, then location verification accuracy is enhanced, but the procedure complexity and timing coordination requirements increase
Solution Approach 1:
The patent applies preliminary action by having the UE pre-calculate timing advance values based on its GNSS location and the satellite's ephemeris data before the actual measurement occasions. The UE determines multiple measurement occasions in advance and prepares timing advance reports that are linked to specific transmission times, eliminating the need for complex real-time coordination.
Solution Approach 2:
The patent introduces timing advance reports as an intermediary mechanism. Instead of directly performing complex multi-RTT measurements, the UE generates timing advance reports based on GNSS and ephemeris data, which then serve as the basis for location verification. This intermediary approach simplifies the overall procedure while maintaining accuracy.
3Measurement precision
If traditional positioning methods are used in NTN, then the system structure remains simple, but timing errors caused by satellite movement cannot be minimized
Solution Approach 1:
The patent addresses satellite movement dynamics by using updated ephemeris data that accounts for the satellite's changing position and velocity. The UE calculates timing advance values dynamically based on the current satellite state, and the network can update measurement occasions to account for Doppler shifts and other dynamic effects, thereby minimizing timing errors.
Solution Approach 2:
The patent implements feedback mechanisms where the UE transmits timing advance reports to the network, which can then use this information to adjust future measurement occasions and improve timing accuracy. The network provides feedback about satellite status and measurement results, enabling continuous refinement of positioning accuracy.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the accuracy of UE location verification in NTN environments by leveraging GNSS and ephemeris data to calculate precise timing advances, reducing errors associated with satellite dynamics and improving geometric diversity for multilateration, thereby ensuring precise UE positioning.
Implementation Method 1
The UE determines multiple uplink measurement occasions for transmitting multiple reference signals to a satellite in a non-terrestrial network (NTN). The UE generates, based on Global Navigation Satellite System (GNSS) location data of the UE and ephemeris data of the satellite, multiple timing advance (TA) reports
Implementation Method 2
The UE transmits the multiple uplink reference signals to the satellite on the uplink measurement occasions. The satellite transmits downlink reference signals to the UE on multiple downlink measurement occasions
Data Source
AI summary
In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a UE. The UE determines multiple uplink measurement occasions for transmitting multiple reference signals to a satellite in a non-terrestrial network (NTN). The UE generates, based on Global Navigation Satellite System (GNSS) location data of the UE and ephemeris data of the satellite, multiple timing advance (TA) reports that are linked to the multiple uplink measurement occasions, respectively. The UE transmits the multiple TA reports to the satellite at multiple time points. The UE transmits the multiple uplink reference signals to the satellite on the uplink measurement occasions.