PTRS Reception Using DMRS Interpolation for Phase Tracking
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Solution Overview
Problem
Existing wireless communication systems face challenges in accurately estimating and compensating for phase noise, particularly in high-frequency bands like mmWave, which affects channel estimation and leads to significant interference and degradation.
Innovation Solution
A method and apparatus for receiving a phase tracking reference signal (PTRS) that involves performing linear interpolation and calculating a common phase error (CPE) angle difference based on DMRS-assigned resource elements to enhance phase tracking and channel estimation accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If linear interpolation is performed based on two DMRS-assigned resource elements to acquire channel frequency response estimation, then channel estimation accuracy is improved, but calculation complexity increases
Solution Approach 1:
The patent performs linear interpolation based on two DMRS-assigned resource elements to pre-acquire channel frequency response estimation values before PTRS reception. This preliminary channel estimation is then refined by calculating CPE angle differences, resolving the contradiction by preparing accurate baseline estimates in advance that reduce the complexity of subsequent phase tracking operations.
Solution Approach 2:
The patent introduces CPE angle difference calculation as an intermediary step between DMRS-based channel estimation and final PTRS phase tracking. This intermediary mechanism bridges the gap between rough interpolation-based estimates and precise phase tracking, improving accuracy while managing computational complexity through a structured multi-stage approach.
2Measurement precision
If CPE angle difference calculation is applied to refine channel estimation, then phase tracking accuracy is improved, but processing time increases
Solution Approach 1:
The patent calculates CPE angle differences based on already-acquired channel frequency response estimation values from DMRS resource elements. By performing this calculation in advance of final phase tracking and using pre-computed interpolation results, the system improves phase tracking accuracy while minimizing additional processing time requirements.
Solution Approach 2:
The patent transforms the channel estimation problem by changing parameters from direct PTRS-based estimation to a two-stage process using DMRS-based interpolation followed by CPE angle difference calculation. This parameter transformation allows accurate phase tracking while controlling processing time by leveraging existing DMRS measurements rather than requiring additional PTRS processing.
3Measurement precision
If DMRS-assigned resource elements are used for linear interpolation, then channel frequency response estimation is improved, but resource overhead increases
Solution Approach 1:
The patent makes DMRS-assigned resource elements serve multiple functions: they provide both demodulation reference signals for data detection and channel frequency response estimation for phase tracking. By enabling DMRS to fulfill dual purposes, the system improves channel estimation accuracy without requiring additional dedicated pilot signals, thus avoiding increased resource overhead.
Solution Approach 2:
The patent enables the existing DMRS structure to self-serve the additional function of channel frequency response estimation for PTRS phase tracking. Rather than requiring separate resources, the DMRS elements automatically provide the necessary estimation data through linear interpolation, making the system self-sufficient and avoiding additional resource consumption.
Data Source
AI summary
The present disclosure describes a method and apparatuses for a UE or a base station to receive a phase tracking reference signal (PTRS) in a wireless communication system. The method by which a UE receives a PTRS in a wireless communication system, according to various embodiments, may comprise: acquiring a first CFR estimate value in a resource element (RE) to which the PTRS has been allocated, by performing linear interpolation on the basis of two REs to which a demodulation reference signal (DMRS) has been allocated; calculating an estimate value a CPE angle difference for the RE to which the PTRS has been allocated; and on the basis of a second CFR estimate value acquired by applying the estimate value of the CPE angle difference to the first CFR estimate value, performing phase tracking of the RE to which the PTRS has been allocated.