UE Location via Signal Travel Time and Bias Suppression

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Solution Overview

Problem

Conventional satellite-based positioning systems are unreliable for indoor applications due to the lack of direct line of sight with satellites and the presence of obstacles that cause signal reflections and multipath issues, leading to inaccurate location determination.

Innovation Solution

The use of terrestrial signal sources, such as indoor wireless access points, to determine the location of a user equipment (UE) device through signal travel time measurements and bias suppression techniques, leveraging both timing-based multilateration and signal-strength-based fingerprint databases.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If satellite-based positioning systems are used for indoor location determination, then the system can provide location services, but the accuracy deteriorates due to lack of direct line of sight and signal reflections

Engineering Contradiction:

Improvepositioning reliabilityVSAvoidlocation accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent introduces terrestrial signal sources (wireless access points) as intermediary elements to enable positioning indoors. These access points serve as mediators between the UE and the positioning system, allowing location determination without direct satellite visibility by using terrestrial-based signal travel time measurements

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces satellite-based electromagnetic positioning with terrestrial signal-based positioning. By substituting the satellite signal source with local wireless access points, the system adapts the positioning mechanism to work effectively in indoor environments where satellite signals are blocked

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If signal travel time measurements are used for location determination, then the system can calculate position, but measurement bias increases due to non-line-of-sight paths and multipath communications

Engineering Contradiction:

Improvelocation determination capabilityVSAvoidsignal travel time accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent applies preliminary calibration to establish bias suppression data before actual positioning operations. By pre-characterizing the environment and storing bias information in a database, the system prepares correction factors in advance that can be applied during real-time location determination to compensate for multipath and NLoS effects

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements a feedback mechanism where measured signal travel times are compared against calibrated expectations, and bias suppression is applied based on the difference. This feedback loop continuously corrects measurements to improve accuracy in the presence of multipath communications

Inventive Principle:

Principle #23Feedback

3Adaptability or versatility

If conventional positioning systems are used indoors, then basic location services are provided, but the accuracy is insufficient for applications requiring precise location determination

Engineering Contradiction:

Improveindoor positioning capabilityVSAvoidlocation accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent segments the positioning problem into two parts: (1) obtaining raw signal travel time measurements from multiple access points, and (2) applying bias suppression using pre-calibrated data. This segmentation allows the system to maintain adaptability for various indoor environments while improving precision through specialized correction techniques

Inventive Principle:

Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach provides highly accurate and precise location determination for UE devices indoors and outdoors, effectively addressing the challenges of non-line-of-sight signal paths and multipath communications by compensating for measurement biases using pre-calibrated data.

Implementation Method 1

determine a time measurement indicative of a signal travel time between a user equipment (UE) device and an access point (AP) device

Methodology Applied

Scientific EffectSignal travel time measurement: Time of Flight

Data Source

PatentUS20250028044A1Methods and systems for locating a user equipment device based on signal travel time and bias suppression

Publication Date: 2025.01.23 VERIZON PATENT & LICENSING INC

AI summary

An illustrative UE locator system determines a time measurement indicative of a signal travel time between a UE device and an access point device. The signal travel time corresponds to an apparent distance, presuming a line-of-sight (LoS) signal travel path, between a location of the UE device and a location of the access point device. The UE locator system also accesses, from a bias suppression datastore, bias suppression data configured for use in suppressing an influence of a bias between the apparent distance and a true distance between the location of the UE device and the location of the access point device. Based on the time measurement and the bias suppression data, the UE locator system estimates the location of the UE device. Corresponding methods and systems are also disclosed.