5G NR Positioning with PTRS-Assisted PRS Phase Noise Correction

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Solution Overview

Problem

5G New Radio (NR) networks operating in mmWave bands suffer from phase noise, which significantly affects the accuracy of position fixes due to the impact on phase tracking reference signals, leading to reduced performance in location services.

Innovation Solution

Implementing Phase Tracking Reference Signals (PTRS) with Positioning Reference Signals (PRS) to correct phase offsets and minimize the impact of phase noise, using specific PRS frame structures and staggered symbols to estimate and correct phase errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If Phase Tracking Reference Signals (PTRS) are transmitted with Positioning Reference Signals (PRS) to correct phase offsets, then positioning accuracy is improved, but device complexity and signal processing complexity increase

Engineering Contradiction:
Improvepositioning accuracyVSAvoidsignal processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the positioning signal into two distinct components: Positioning Reference Signals (PRS) for carrying positioning information and Phase Tracking Reference Signals (PTRS) for correcting phase offsets. This segmentation allows each signal type to be optimized for its specific function, with PTRS providing focused phase correction capability that improves positioning accuracy without overwhelming the system with complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

PTRS acts as an intermediary element between the PRS and the positioning measurement process. The PTRS signals are inserted at specific positions within the PRS frame structure to mediate phase errors, providing a reference for phase correction that indirectly improves positioning accuracy without requiring fundamental changes to the PRS design.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If specific PRS frame structures with staggered symbols are used to estimate and correct phase errors, then positioning accuracy is improved, but the complexity of signal configuration and processing increases

Engineering Contradiction:
Improvepositioning accuracyVSAvoidsignal configuration complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent modifies the frame structure parameters of PRS by introducing staggered symbol configurations with specific timing offsets. These parameter changes create a structured pattern that enables phase error estimation through comparison of staggered symbols, transforming the phase noise problem into a measurable parameter that can be corrected through standard signal processing techniques.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If PTRS is transmitted alone or with PRS to minimize phase noise impact, then positioning accuracy is improved, but transmission overhead and resource utilization increase

Engineering Contradiction:
Improvepositioning accuracyVSAvoidtransmission overhead
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The PTRS signals are designed to serve multiple functions simultaneously: they provide phase tracking for data channels, phase correction for positioning measurements, and reference signals for channel estimation. This multi-functionality allows the same signal infrastructure to support both communication and positioning requirements, reducing overall transmission overhead compared to having separate dedicated signals for each function.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4042179B1Method and apparatus for 5g positioning accuracy improvement in presence of phase noise
Publication Date: 2025.11.05 QUALCOMM INC
  • EP4042179B1 patent drawingFigure 1
  • EP4042179B1 patent drawingFigure 2
  • EP4042179B1 patent drawingFigure 3A

AI summary

A mobile device and base station are enabled to support improved positioning accuracy in the presence of phase noise in high frequency radio network, such as in 5G New Radio network operating in mm Wave. Phase Tracking Reference Signal (PTRS) may be transmitted with Positioning Reference Signals (PRS) and used for positioning and/or used to correct the phase offset between symbols in the PRS (1302). A request may be made to transmit PTRS alone or with the PRS, or that the PRS is transmitted with a specific PRS frame structure, e.g., with a specific comb value, that minimizes the impact of phase noise. The PTRS or a phase ramp of the staggered symbols in the PRS may be used to estimate and correct the phase offset (1304, 1306).