Local Wave Propagation Model for Receiver Positioning

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Solution Overview

Problem

Existing positioning systems relying on known transmitter locations are limited by the need for accurate transmitter location data, which can lead to errors due to signal reflections and distortions, and require extensive databases of transmitter locations.

Innovation Solution

A method using a local wave propagation model to determine the position of a receiver device without needing accurate transmitter location information, allowing the use of reflected signals and reducing errors by modeling signal behavior in the local neighborhood.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If transmitter location is used as reference for positioning, then positioning can be achieved, but accuracy deteriorates due to errors in transmitter location and signal reflections

Engineering Contradiction:
Improvepositioning accuracyVSAvoiddependence on transmitter location accuracy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent introduces a local wave propagation model as an intermediary between the transmitter and receiver. Instead of directly relying on transmitter location data, the model mediates the positioning calculation by accounting for local environmental factors such as signal reflections, refraction, and propagation speed variations. This intermediary model allows accurate positioning even when transmitter location data is inaccurate or unavailable.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent applies local quality by creating a positioning model specific to the local environment rather than using a general global model. The local wave propagation model incorporates environment-specific characteristics such as building structures, terrain features, and local signal propagation patterns. This localized approach improves positioning accuracy by accounting for local factors that affect signal behavior, rather than assuming uniform propagation conditions.

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If extensive database of transmitter locations is maintained, then more signals can be used for positioning, but system complexity increases

Engineering Contradiction:
Improvenumber of usable signalsVSAvoiddatabase requirements
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent extracts the essential information needed for positioning from the complex database of transmitter locations. Instead of requiring complete and accurate transmitter location data, the system extracts only the necessary propagation characteristics and uses the local wave propagation model to infer positioning information. This extraction approach reduces the complexity of data management while maintaining positioning capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent creates a simplified copy of the positioning function that does not depend on the full transmitter location database. The local wave propagation model acts as a computational copy that reproduces positioning results using simplified local environmental data rather than comprehensive transmitter databases. This copying approach reduces system complexity while preserving the essential positioning function.

Inventive Principle:
Principle #26Copying

3Device complexity

If direct line-of-sight propagation is assumed, then calculations are simplified, but positioning accuracy deteriorates due to reflections and distortions

Engineering Contradiction:
Improvecalculation simplicityVSAvoidpositioning accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent applies dynamics by transitioning from a static direct line-of-sight assumption to a dynamic wave propagation model that accounts for changing signal paths. The local wave propagation model dynamically adapts to reflect the actual signal behavior including reflections, refraction, and diffraction. This dynamic approach maintains calculation feasibility while significantly improving positioning accuracy by representing the actual propagating signal paths rather than assuming idealized straight-line propagation.

Inventive Principle:
Principle #15Dynamics

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 enables accurate positioning without relying on known transmitter locations, using a local wave propagation model to calculate the receiver's position based on signal arrival times and direction of propagation, reducing errors and simplifying database requirements.

Implementation Method 1

obtaining a local wave propagation model of the signal, the model comprising an estimate of the direction of propagation of the signal in the neighbourhood of the reference position and unknown position

Methodology Applied
Scientific EffectWave propagation:

Data Source

PatentEP2634593B1Positioning using a local wave-propagation model
Publication Date: 2016.11.09 U-BLOX
  • EP2634593B1 patent drawingFigure 1
  • EP2634593B1 patent drawingFigure 2
  • EP2634593B1 patent drawingFigure 3

AI summary

A method and apparatus for assisting the calculation of the position of a receiver device (1200), by observing a transmitted signal having a known structure. The method comprises: comparing (S220) the time of arrival, at a reference position (X1), of a first portion of the signal with the time of arrival at the receiver, at an unknown position (Y1), of a second portion of the signal; obtaining (S230) a local wave propagation model of the signal, the model comprising an estimate of the direction of propagation of the signal in the neighbourhood of the reference position and unknown position; and using (S240) the direction of propagation and the result of the comparison to assist in the calculation of the unknown position relative to the reference position.