Mobile Device Location Using Light and RF Signal Merging

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In large venues, light-based communication systems for mobile device location determination face ambiguity due to limited unique fixture identifiers and partial decoding of codewords, leading to multiple possible position solutions.

Innovation Solution

A method and apparatus for a processor-based mobile device to determine a first set of candidate positions based on decoded identifiers from light-based communications, and select a single candidate position to resolve positional ambiguity using further position data from additional signals, such as RF signals or light-based communications received at different time instances.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If light-based communication systems are used for location determination in large venues, then location determination capability is provided, but positional ambiguity occurs due to limited unique fixture identifiers and partial decoding of codewords

Engineering Contradiction:

Improvelocation determination capabilityVSAvoidposition accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent combines multiple signal sources (light-based communications from multiple light devices and RF signals from wireless devices) to determine mobile device position. By merging these different communication types, the system resolves positional ambiguity that would occur when using light-based communications alone, especially in large venues with limited unique identifiers.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent uses an intermediary processing approach where the mobile device receives and processes both light-based communications and RF signals, then combines this information to determine position. This intermediary step of integrating multiple signal types acts as a mediator to resolve the ambiguity problem caused by limited unique identifiers in the light-based system alone.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Loss of information

If multiple light devices transmit light-based communications with codewords, then location information can be obtained, but partial decoding of codewords leads to multiple possible position solutions

Engineering Contradiction:

Improvecodeword decoding completenessVSAvoidposition determination accuracy

Core Design Contradiction:

Loss of informationVSMeasurement precision

Solution Approach 1:

The patent changes the parameter of signal type diversity by incorporating both light-based communications and RF signals into the position determination process. This parameter change allows the system to compensate for partial codeword decoding issues in light-based communications alone, as the additional RF signal information provides supplementary data to resolve multiple possible position solutions.

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If the number of unique fixture identifiers is limited to around a few thousand, then system complexity is reduced, but location determination becomes ambiguous in large venues with more than a few thousand fixtures

Engineering Contradiction:

Improveidentifier system complexityVSAvoidcoverage area capacity

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent makes the positioning system universal by enabling it to function effectively in both small and large venues through multi-functionality. By incorporating both light-based communications (effective for closer ranges with limited identifiers) and RF signals (effective for larger areas with more fixtures), the system adapts to different venue sizes and identifier quantities, resolving the ambiguity problem in large venues while maintaining simplicity in smaller ones.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 effectively resolves positional ambiguity by utilizing additional position data to select the most accurate candidate position, improving location determination accuracy in environments with limited unique identifiers and partial decoding issues.

Implementation Method 1

receiving and processing the modulated visible light signal at a receiver (e.g., a mobile device) that includes a photo detector (PD) or array of PDs

Methodology Applied

Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentUS10006986B2Location determination using light-based communications

Publication Date: 2018.06.26 QUALCOMM INC

AI summary

Disclosed are methods, systems, devices, apparatus, computer-/processor-readable media, and other implementations, including a method, at a processor-based mobile device, that includes determining a first set of candidate positions of the mobile device corresponding to a first time instance based, at least in part, on position data including a first set of identifiers decoded from signals including respective first one or more light-based communications received by the mobile device from a first one or more light devices, with the mobile device being located at a first location at the first time instance. The method further includes selecting at least one candidate position from the first set of candidate positions, in response to a determination that the first set of candidate positions includes more than one candidate position, in order to resolve positional ambiguity, based, at least partly, on further position data from further signals from one or more devices.