Uplink Positioning Reference Signal Configuration for 5G Location Accuracy

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Solution Overview

Problem

Current positioning methods in wireless communication systems, such as 5G NR, face challenges in reducing latency and improving accuracy due to limitations in uplink positioning reference signals (UL PRS) related to power constraints and beam pairing latency, which affect the determination of user equipment (UE) location.

Innovation Solution

The system configures user equipment (UE) to transmit UL PRS with specific beams, allowing base stations to measure angle of arrival, signal strength, and timing information, which is then used by a network server to perform outlier rejection and optimize downlink positioning reference signals (DL PRS) scheduling, reducing latency and improving positioning accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If downlink positioning reference signals (DL PRS) are used for positioning measurements, then positioning accuracy can be achieved, but latency increases and messaging overhead increases

Engineering Contradiction:
Improvepositioning accuracyVSAvoidlatency
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies preliminary action by having the UE transmit UL PRS before the network server determines the location. The base stations measure the UL PRS in advance to obtain angle of arrival and timing information, which is then used to calculate the UE's location. This preliminary measurement approach eliminates the need for separate DL PRS transmission and measurement, thereby reducing latency while maintaining positioning accuracy.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent inverts the traditional positioning approach by using uplink signals (UL PRS) instead of downlink signals (DL PRS) for positioning measurements. Instead of the network transmitting DL PRS to the UE for measurement, the UE transmits UL PRS to base stations for measurement. This inversion reduces messaging overhead and latency while achieving the same positioning accuracy.

Inventive Principle:
Principle #13The other way round (Inversion)

2Measurement precision

If uplink positioning reference signals (UL PRS) are transmitted with multiple beams, then positioning accuracy improves, but power consumption increases

Engineering Contradiction:
Improvepositioning accuracyVSAvoidpower consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent applies partial action by having the UE transmit UL PRS with a limited set of beams rather than exhaustively sweeping all possible beams. The base stations measure the angle of arrival to determine the dominant direction, which provides sufficient positioning accuracy without requiring the UE to transmit with all possible beams, thereby reducing power consumption while maintaining adequate positioning precision.

Inventive Principle:
Principle #16Partial or excessive action

3Measurement precision

If beam pairing is performed for positioning measurements, then positioning accuracy improves, but latency increases

Engineering Contradiction:
Improvepositioning accuracyVSAvoidbeam pairing latency
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent eliminates beam pairing latency by performing preliminary angle of arrival measurements on UL PRS before DL PRS transmission is configured. The base stations measure the angle of arrival of UL PRS to determine the spatial relationship between the UE and base stations in advance. This preliminary action provides the necessary directional information without requiring time-consuming beam pairing procedures, thereby reducing latency while maintaining positioning accuracy.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4291916B1Measurement of uplink positioning reference signals
Publication Date: 2025.03.19 QUALCOMM INC
  • EP4291916B1 patent drawingFigure 1
  • EP4291916B1 patent drawingFigure 2
  • EP4291916B1 patent drawingFigure 3

AI summary

Techniques are provided for managing positioning reference signals in communication networks. An example method of measuring downlink positioning reference signals includes transmitting one or more uplink positioning reference signals measurements, receiving downlink positioning reference signal configuration information associated at least in part with the one or more uplink positioning reference signal measurements, and measuring one or more downlink positioning reference signals based at least in part on the downlink positioning reference signal configuration information.