Biometric Device Using Multi-Antenna Signal Correlation

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Solution Overview

Problem

Existing biometric devices using electromagnetic waves for living body discrimination are limited in flexibility and accuracy, particularly when the subject is not seated, as they require specific orientations and distances between antennas and the subject, and struggle with noise and accidental coincidences.

Innovation Solution

A biometric device with multiple transmission and reception antennas arranged around the subject to receive reflection signals over a prolonged period, calculating correlation coefficients to accurately identify living bodies regardless of orientation, using a teacher signal and cumulative distribution functions to enhance discrimination accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple antennas are arranged around the subject to receive reflection signals, then living body discrimination accuracy is improved, but device complexity increases

Engineering Contradiction:
Improveliving body discrimination accuracyVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system divides the antenna array into multiple receivers (first receiver, second receiver, third receiver, fourth receiver) positioned at different locations around the subject. Each receiver independently captures reflection signals from specific directions, and the signals are subsequently synthesized to achieve comprehensive 360-degree coverage and improved discrimination accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent combines reflection signals from multiple receivers through signal synthesis. The first and second receivers capture signals from one direction while the third and fourth receivers capture signals from another direction, and these signals are merged to form a comprehensive biometric signature that improves living body discrimination accuracy.

Inventive Principle:
Principle #5Merging (Combining)

2Measurement precision

If the measurement period is prolonged to improve discrimination accuracy, then measurement precision is improved, but loss of time increases

Engineering Contradiction:
Improvediscrimination accuracyVSAvoidmeasurement time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system continuously receives reflection signals from multiple receivers simultaneously over a predetermined period. By maintaining continuous signal acquisition from all receivers in parallel, the system accumulates sufficient biometric data quickly, achieving high discrimination accuracy without requiring excessively long measurement times.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent performs preliminary signal processing by synthesizing signals from multiple receivers before final discrimination analysis. This preliminary synthesis prepares the combined biometric signature in advance, enabling faster and more accurate living body discrimination without requiring extended measurement periods.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If specific orientation and distance requirements are imposed on antennas and subject, then measurement precision is improved, but adaptability deteriorates

Engineering Contradiction:
Improvemeasurement precisionVSAvoidadaptability
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The system is designed to receive reflection signals from multiple directions simultaneously using receivers positioned at different locations. This multi-directional signal reception capability allows the system to accurately measure biometric signatures regardless of the subject's orientation or position, making the system universally applicable in various seating arrangements and body positions.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent transitions from single-direction signal reception to multi-directional 360-degree signal acquisition by arranging receivers around the subject. This spatial dimensionality change enables the system to capture reflection signals from all directions, eliminating the need for specific subject orientation and significantly improving adaptability.

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

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

The device achieves flexible and accurate living body discrimination with reduced measurement times and improved noise rejection, allowing for effective identification in various situations, including different orientations and positions of the subject.

Implementation Method 1

at least one transmission antenna element that transmits a transmission signal to a predetermined range including the living body

Methodology Applied
Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Implementation Method 2

N reception signals including a reflection signal resulting from the transmission signal reflected off the living body

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP3289971B1Biometric device and biometric method
Publication Date: 2021.10.20 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP3289971B1 patent drawingFigure 1
  • EP3289971B1 patent drawingFigure 2~3
  • EP3289971B1 patent drawingFigure 4~5

AI summary

A device that differentiates a living body includes at least one transmission antenna element that transmits a transmission signal to a predetermined range including the living body, N receivers that are arranged to surround a periphery of the predetermined range and each receive N reception signals using respective reception antenna elements of the receivers during a predetermined period, the N reception signals including a reflection signal resulting from the transmission signal reflected off the living body, memory that stores a teacher signal, a circuit that calculates a plurality of correlation coefficients according to the teacher signal and the N reception signals received by the N receivers and determines that the living body and the subject living body are identical to each other when a predetermined correlation coefficient included in the plurality of correlation coefficients is included in a predetermined value range.