Dynamic PT-RS Frequency Patterns for Phase Tracking

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Solution Overview

Problem

Current wireless communication systems, particularly in 5G NR, face challenges in phase tracking due to phase errors caused by phase noise, carrier frequency offset, and Doppler shift, leading to increased bit error rates and reduced throughput, especially in millimeter wave systems.

Innovation Solution

The system selects and transmits optimized frequency domain patterns for phase tracking reference signals (PT-RS) based on channel conditions and scheduled bandwidth, allowing for dynamic adjustment of PT-RS density and location to improve phase error estimation and tracking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If phase tracking reference signals are transmitted with fixed density and location, then system complexity is reduced, but phase tracking accuracy deteriorates under varying channel conditions

Engineering Contradiction:
Improvephase tracking accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements dynamic selection of PT-RS frequency domain patterns based on scheduled bandwidth and channel conditions. The system transitions from fixed-density PT-RS transmission to adaptive density adjustment, where the density parameter is modified according to actual communication requirements, thereby resolving the contradiction between maintaining simplicity and achieving accuracy under varying conditions

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the density and location parameters of PT-RS in the frequency domain based on scheduled bandwidth and channel conditions. By dynamically adjusting these parameters, the system optimizes phase tracking accuracy for different operating scenarios without requiring complete redesign of the reference signal structure

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If PT-RS density is increased to improve phase tracking accuracy, then phase error estimation improves, but resource overhead increases

Engineering Contradiction:
Improvephase error estimation accuracyVSAvoidresource overhead
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent applies different PT-RS densities at different frequency locations based on scheduled bandwidth requirements. Instead of uniformly increasing density across all frequencies, the system selectively places PT-RS resources where they are most needed, optimizing phase error estimation accuracy while minimizing overall resource overhead

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent implements partial action by transmitting PT-RS only at selected frequency locations rather than continuously across all subcarriers. The density is adjusted to provide sufficient phase tracking capability without excessive resource consumption, achieving the optimal balance between accuracy and overhead

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3937416B1Systems and methods to select or transmitting frequency domain patterns for phase tracking reference signals
Publication Date: 2023.03.01 QUALCOMM INC
  • EP3937416B1 patent drawingFigure 1
  • EP3937416B1 patent drawingFigure 2A~2D
  • EP3937416B1 patent drawingFigure 3

AI summary

A wireless communication device that selects a recommendation for a resource to transmit a phase tracking reference signal, PT-RS, based on a condition of a communication system, transmit a at least one of information or a reference signal to assist in determining the resource, and receiving a transmission indicating a PT-RS transmission. Another wireless communication that receives at least one of information or a reference signal to assist in determining the resource, determines a time-frequency resource based on the received at least one of information or a reference signal and transmits a transmission providing a resource for a PT-RS. Also included are associated methods.