Acoustic Positioning Deconvolution Decoder for Multi-Path Interference

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Solution Overview

Problem

Indoor real-time location systems face challenges in accurately determining the location of moving mobile communication devices due to Doppler shifts and multi-path interference, which affects the accuracy of identity and position determination in indoor environments.

Innovation Solution

A method involving a mobile communication device that receives acoustic signals, correlates them with a magnitude block window to identify signal peaks, deconvolves these peaks with code keys exceeding a signal-noise-ratio threshold, and determines the likelihood of correctness based on both signal and time of arrival parameters to identify the transmitting device's code key.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional location systems are used, then device positioning is provided, but accuracy is reduced due to Doppler shifts and multi-path interference

Engineering Contradiction:

Improvelocation estimation accuracyVSAvoidsignal accuracy

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent converts the harmful effects of multi-path interference and Doppler shifts into beneficial information. By analyzing the characteristics of reflected signals and frequency shifts, the system identifies valid code keys and determines device location and velocity. The deconvolution decoder specifically exploits signal structure to distinguish direct paths from reflected paths, transforming interference into useful positioning data.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The system changes parameters by jointly analyzing signal-to-noise ratio and time of arrival metrics, and by applying deconvolution techniques that transform the received signal into a form where code keys can be reliably identified. The method modifies the approach from simple signal detection to a comprehensive parameter-based analysis that accounts for environmental effects.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If acoustic signals are received through multiple transmission paths, then signal coverage is improved, but signal identification accuracy deteriorates due to interference

Engineering Contradiction:

Improvesignal reception capabilityVSAvoidcode key identification accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent segments the received acoustic signal into distinct transmission paths by applying deconvolution techniques. The system separates the direct signal from reflected signals by analyzing their temporal and spectral characteristics. This segmentation allows the decoder to identify individual code keys from each path and selectively process valid signals while rejecting interference.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The deconvolution decoder acts as an intermediary that processes the mixed acoustic signals from multiple paths. It uses the known structure of code keys and signal propagation characteristics to filter and identify valid code keys, serving as a mediator between the complex multi-path environment and the final position determination.

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 provides more accurate and efficient location estimation of mobile communication devices with an accuracy of 2.5 to 25 centimeters standard deviation, improving upon conventional systems by accounting for acoustic environment knowledge and mitigating interference effects.

Implementation Method 1

Indoor real-time location systems face challenges in accurately determining the location of moving mobile communication devices due to Doppler shifts and multi-path interference

Methodology Applied

Scientific EffectDoppler shift: Doppler Effect

Implementation Method 2

Indoor real-time location systems face challenges in accurately determining the location of moving mobile communication devices due to Doppler shifts and multi-path interference

Methodology Applied

Scientific EffectMulti-path interference: Interference

Data Source

PatentUS11867826B2Position determination system having a deconvolution decoder using a joint SNR-time of arrival approach

Publication Date: 2024.01.09 SONITOR TECH AS

AI summary

The present disclosure relates to an acoustic position determination system that includes a mobile communication device and at least one base transmitter unit. The mobile communication device is configured to identify a peak in the received signal, and to de-convolve the signal with all codes that are relevant to the area in which the signal is received. A joint likelihood that a potential code is correct is formed by determining a likelihood based on a signal parameter such as signal-to-noise ratio and a likelihood based on time-of arrival information.