Serving Base Station DL-PRS ToA Measurement for UE Positioning

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Solution Overview

Problem

Current wireless communication systems face challenges in accurately measuring the time of arrival (ToA) of downlink positioning reference signals (DL-PRS) from non-serving base stations, which affects precise positioning of user equipment (UE) due to limitations in UL-SRS-P measurement and network synchronization.

Innovation Solution

A method involving a serving base station measuring the ToA of a DL-PRS from a non-serving base station and an uplink sounding reference signal for positioning (UL-SRS-P) from the UE, with the serving base station transmitting measurement information to a position estimation entity for determining the UE's position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If UL-SRS-P measurements are used for positioning, then positioning capability is provided, but measurement quality deteriorates for non-serving base stations

Engineering Contradiction:

Improvepositioning accuracyVSAvoidmeasurement quality

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The serving base station acts as an intermediary to perform DL-PRS measurements that would otherwise need to be performed by the UE. The serving base station receives DL-PRS from non-serving base stations, measures the ToA, and reports the measurements to the location manager, bypassing the need for direct UE measurements of non-serving base station signals

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

Instead of having the UE measure DL-PRS from non-serving base stations directly (which has poor quality), the system inverts the measurement approach by having the serving base station perform the measurements. The serving base station uses its superior reception capability to measure DL-PRS from non-serving base stations and reports these measurements upward to the location manager

Inventive Principle:

Principle #13The other way round (Inversion)

2Measurement precision

If DL-PRS ToA measurement is performed at UE, then positioning information is obtained, but power consumption increases for power-limited devices

Engineering Contradiction:

Improvepositioning accuracyVSAvoidpower consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The serving base station performs the DL-PRS measurements itself using its own reception capabilities, eliminating the need for the power-limited UE to perform these measurements. The UE only needs to transmit UL-SRS-P and process location estimates, significantly reducing its power consumption while maintaining positioning accuracy

Inventive Principle:

Principle #25Self-service

3Device complexity

If network synchronization is assumed for positioning, then positioning calculation is simplified, but positioning accuracy deteriorates due to synchronization limitations

Engineering Contradiction:

Improvepositioning calculation complexityVSAvoidpositioning accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The serving base station performs preliminary DL-PRS ToA measurements and UL-SRS-P measurements before position calculation. By having the serving base station pre-measure the DL-PRS ToA from non-serving base stations and the UL-SRS-P ToA from the UE, the system obtains accurate timing information without requiring perfect network synchronization, and these measurements are then used by the location manager to calculate the UE position

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS12041511B2Measurement of a downlink positioning reference signal from a non-serving base station of a user equipment at a serving base station of the user equipment

Publication Date: 2024.07.16 QUALCOMM INC

AI summary

In an aspect, a serving BS of a UE measures ToAs of a DL-PRS from a non-serving base station of the UE and an UL-SRS-P from the UE. The serving BS transmits measurement information based on the ToA measurements of the DL-PRS and the UL-SRS-P to a position estimation entity. The position estimation entity determines a positioning estimate for the UE based in part upon the measurement information.