NTN Positioning Using Uplink-Downlink Subframe Offset
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Solution Overview
Problem
Existing positioning methods for terminal devices in terrestrial networks are inadequate for non-terrestrial networks (NTN) due to larger coverage and propagation delays, necessitating improved location verification and positioning solutions.
Innovation Solution
A method and apparatus that utilize measurements of downlink and uplink positioning reference signals, including offsets and propagation delays, to determine the location of terminal devices in NTN scenarios, enhancing accuracy through frame number and subframe number alignment and reporting mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing positioning methods for terrestrial networks are used in NTN, then the positioning process is simple, but the positioning accuracy is insufficient due to larger coverage and propagation delays
Solution Approach 1:
The positioning method is segmented into multiple measurement components: downlink positioning reference signal measurement, uplink positioning reference signal measurement, and offset measurement between subframes. Each component contributes to the overall positioning accuracy while maintaining manageable complexity through modular processing.
Solution Approach 2:
The patent introduces a new dimension of measurement by incorporating offset information between downlink and uplink subframes with the same frame and subframe numbers. This temporal-dimension measurement complements the traditional spatial positioning measurements, enabling accurate positioning in NTN's large coverage areas where propagation delays are significant.
2Area of stationary object
If NTN coverage is expanded to provide wider coverage, then the network coverage area increases, but the propagation delay increases making existing positioning methods inadequate
Solution Approach 1:
The patent performs preliminary measurements of the offset between downlink and uplink subframe start locations before using these measurements for positioning calculation. This preliminary action captures the timing characteristics of the NTN link, enabling accurate positioning despite the large propagation delays inherent in expanded coverage areas.
Solution Approach 2:
The positioning method incorporates feedback through the measurement and reporting of offset values between downlink and uplink subframes. This feedback information is used to compensate for propagation delay effects, allowing the system to maintain positioning accuracy across the expanded NTN coverage area.
Data Source
AI summary
A positioning method and a positioning apparatus for a non-terrestrial network (NTN). The method includes: a first device determines a location of a terminal device with reference to a measurement result of an uplink positioning reference signal based on an offset, reported by the terminal device, between a start location of a subframe in which a downlink positioning reference signal is located and a start location of an uplink subframe that has a same frame number and a same subframe number as the subframe and that is closest to the subframe, or based on an offset between a start location of a subframe in which a downlink positioning reference signal is located and a start location of an uplink subframe in which the uplink positioning reference signal sent by the terminal device is located. Therefore, accuracy of the location of the terminal device is improved.