NTN Uplink Frequency Pre-Compensation for DMRS Phase Continuity
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Solution Overview
Problem
In non-terrestrial network (NTN) systems, the rapid changes in Doppler shifts and delays due to satellite movement cause phase discontinuity during joint channel estimation based on DMRS bundles, which are not adequately addressed by existing technologies.
Innovation Solution
A method for wireless communication involves determining frequency compensation segments within a time period based on first information, considering phase continuity requirements, to perform pre-compensation on uplink channels, thereby maintaining phase continuity for effective joint channel estimation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If joint channel estimation is performed based on DMRS bundle in NTN systems, then channel estimation accuracy is improved, but phase continuity cannot be ensured due to satellite movement causing rapid Doppler shifts and delays
Solution Approach 1:
The time period is divided into multiple frequency compensation segments, with each segment corresponding to one or more DMRS bundles. This segmentation allows independent frequency compensation for each segment, enabling phase continuity to be maintained within each segment while accommodating phase shifts between segments due to satellite movement.
Solution Approach 2:
Frequency compensation is performed in advance for each segment based on predicted Doppler shifts and delays. The terminal device determines compensation values before actual transmission, pre-correcting for expected phase changes caused by satellite motion, thereby ensuring phase continuity during joint channel estimation.
2Stability of the object's composition
If frequency compensation segments are determined dynamically based on A-TDW and C-TDW, then phase continuity is maintained, but device complexity increases
Solution Approach 1:
The sizes of A-TDW and C-TDW are dynamically adjusted based on satellite moving speed and antenna switching conditions. This dynamic adaptation allows the system to optimize the balance between maintaining phase continuity and managing processing complexity, with larger windows used when phase stability is high and smaller windows when rapid changes occur.
3Measurement precision
If TA is updated frequently to track satellite movement, then timing accuracy is improved, but phase continuity within DMRS bundle is broken
Solution Approach 1:
The time period is divided into multiple frequency compensation segments, with each segment corresponding to one or more DMRS bundles. This segmentation allows independent frequency compensation for each segment, enabling phase continuity to be maintained within each segment while accommodating phase shifts between segments due to satellite movement.
Solution Approach 2:
Frequency compensation values are adjusted for each segment based on predicted Doppler shifts and delays. By changing compensation parameters segment-by-segment rather than applying a single continuous correction, the system can track satellite movement while maintaining phase continuity within each DMRS bundle segment.
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 ensures phase continuity during joint channel estimation in NTN systems, improving the accuracy of uplink channel estimation and demodulation performance.
Implementation Method 1
satellite movement may cause rapid changes in Doppler shifts and delays, resulting in a large phase shift in the time domain window corresponding to the DMRS bundle
Data Source
AI summary
A method and an apparatus for wireless communication are provided. One example method includes: determining, by a terminal device operating in a non-terrestrial network (NTN) system, a plurality of frequency compensation segments within a first time period based on first information, wherein the first information comprises information of demodulation reference signal (DMRS) bundle used for joint channel estimation, and the first time period comprises at least one time domain window corresponding to the DMRS bundle; and performing, by the terminal device, pre-compensation on an uplink channel corresponding to the first time period based on the plurality of frequency compensation segments.