Out-of-Hearing Band Audio Signatures for Wireless Device Localization

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Solution Overview

Problem

Existing localization technologies for wireless user equipment (UE) devices in spatial configurations, such as vehicles or home entertainment systems, face challenges in accurately determining the device's position using audio signatures without interfering with human hearing or background audio signals.

Innovation Solution

The method involves capturing and processing out-of-hearing band audio signatures, such as pseudo-random noise sequences or single-frequency tones, transmitted by a head unit to determine the UE device's location relative to a spatial configuration, using techniques like audio masking and Fourier Transform analysis to estimate delays or power dissipation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If audio signatures are transmitted in the audible frequency range to enable localization, then the localization function can be implemented, but it interferes with human hearing and background audio signals

Engineering Contradiction:
Improvelocalization accuracyVSAvoidinterference with human hearing and background audio
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The audio spectrum is segmented into audible range (20Hz-20kHz) and out-of-hearing band range (above 20kHz). Localization audio signatures are transmitted only in the out-of-hearing band portion, separating the localization function from the audible audio function, thereby eliminating interference with human hearing while maintaining localization accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extends the audio frequency dimension beyond the traditional audible range into the ultrasonic/out-of-hearing band region. By utilizing frequencies above 20kHz that are invisible to human ears, the system adds a new operational dimension for localization that does not conflict with audible audio content.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Object-affected harmful factors

If out-of-hearing band audio signatures are used for localization, then interference with human hearing is avoided, but the complexity of signal processing increases

Engineering Contradiction:
Improveinterference with human hearingVSAvoidsignal processing complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The system changes the frequency parameter of audio signatures to the out-of-hearing band (above 20kHz). This parameter change enables the use of specialized processing techniques such as Fourier Transform analysis and autocorrelation that are optimized for ultrasonic signals, managing the complexity through targeted algorithm selection rather than general-purpose processing.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces traditional time-domain signal processing with frequency-domain analysis using Fourier Transform. This substitution allows for more efficient processing of out-of-hearing band signals by transforming the complex time-varying ultrasonic signals into frequency spectra where pattern recognition and delay estimation become more manageable operations.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If multiple audio signatures are transmitted simultaneously from multiple speakers for accurate localization, then positioning precision improves, but signal interference between channels increases

Engineering Contradiction:
Improvepositioning precisionVSAvoidsignal interference between channels
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The system employs periodic transmission of audio signatures from multiple speakers in sequence rather than continuous simultaneous transmission. Each speaker transmits its signature during designated time intervals, creating a periodic pattern that allows the receiving device to distinguish between different speakers through time-based separation, reducing inter-channel interference while maintaining positioning precision.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent introduces channel-specific pseudo-random noise sequences as intermediary signals that modulate the audio signatures from different speakers. These unique noise patterns act as identifiers that allow the receiving device to separate and process signals from different speakers even when transmitted simultaneously, reducing interference through code division multiplexing.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 precise localization of UE devices within spatial configurations while avoiding human perception of the audio signatures, allowing for the modulation of device features based on location, enhancing safety and usability.

Implementation Method 1

capturing a plurality of audio signatures received from a head unit via an audio transmission system having a plurality of speaker channels

Methodology Applied
Scientific EffectSound: Sound

Implementation Method 2

using techniques like audio masking and Fourier Transform analysis to estimate delays or power dissipation

Methodology Applied
Scientific EffectAudio masking:

Implementation Method 3

using techniques like audio masking and Fourier Transform analysis to estimate delays or power dissipation

Methodology Applied
Scientific EffectFourier Transform:

Data Source

PatentEP2708911B1Localization of a wireless user equipment (EU) device based on out-of-hearing band audio signatures for ranging
Publication Date: 2019.02.20 BLACKBERRY LTD
  • EP2708911B1 patent drawingFigure 1~2
  • EP2708911B1 patent drawingFigure 3
  • EP2708911B1 patent drawingFigure 4

AI summary

A scheme for localizing a wireless user equipment (UE) device's relative position with respect to a spatial configuration (101, 201) based on audio signatures received via a multi-channel audio system, e.g., an audio system of a vehicle (106A-106D) or home entertainment system (204A-204D). The wireless UE device (500) is configured to capture the audio signatures received from a head unit (102, 202) that are placed in an out-of-hearing band of a captured signal. The wireless UE device (500) includes a persistent memory module (535) having program instructions for processing the captured signal including the out-of-band signatures, which may comprise either channel-specific pseudo-random noise (PN) sequences or single-frequency tones, in order to compute time delays or power levels associated with the speaker channels. A localization module (550) is configured to estimate the wireless UE device's relative position based on the time delays or power levels.