Acoustic Signal Coding Dictionary Construction via Correlation Filtering

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing acoustic signal coding methods, such as DTMF, lack protection against interception and are complex to implement for confidentiality and integrity, especially against cryptanalysis attacks.

Innovation Solution

A method using random acoustic signals to construct a coding dictionary by filtering and correlating subsets of signals, transforming them into acoustic signals for transmission, and correlating received signals with the dictionary to decode information symbols, providing a simple and robust confidentiality solution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If encryption algorithms are used to guarantee confidentiality, then security is improved, but implementation complexity increases

Engineering Contradiction:
ImproveconfidentialityVSAvoidimplementation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex cryptographic algorithms with a physical/acoustic system using random signal generation and correlation. Instead of mathematical encryption, the system uses acoustic transducers to generate and detect random signals, where the receiver correlates received signals with stored reference signals to decode information. This substitution of mathematical complexity with physical signal processing resolves the contradiction between security and implementation simplicity.

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

Solution Approach 2:

The patent changes the fundamental parameter of security from cryptographic key strength to acoustic signal randomness and correlation properties. By using random acoustic signals with specific statistical properties and correlation matrices, the system achieves confidentiality through physical signal characteristics rather than mathematical encryption, thereby reducing implementation complexity while maintaining security.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If DTMF encoding is used for data transmission, then ease of operation is improved, but security against interception deteriorates

Engineering Contradiction:
Improveease of transmissionVSAvoidsecurity
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies preliminary action by pre-generating and storing random acoustic signal templates at the receiver before actual data transmission. The receiver prepares correlation filters with these random signal patterns in advance, enabling secure decoding to be performed simply by correlating received signals with the pre-stored templates. This maintains ease of operation while achieving security through the randomness of the pre-prepared signals.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If random acoustic signals are used for coding, then confidentiality is improved, but signal processing complexity increases

Engineering Contradiction:
ImproveconfidentialityVSAvoidsignal processing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the essential security function from complex random signal processing by isolating the correlation operation. Instead of processing entire random signals through complex algorithms, the system extracts and correlates only the essential signal features using simple correlation filters. This extraction of the core function maintains confidentiality while reducing overall signal processing complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

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 method ensures confidentiality and simplicity in data transmission by using random acoustic signals, making it difficult for third parties to intercept and decode the information, while being robust against attacks.

Implementation Method 1

each random signal from the dictionary being transformed into an acoustic signal by means of a transducer

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

for each subset, a correlation matrix of the signals thus selected is calculated

Methodology Applied
Scientific EffectCorrelation:

Data Source

PatentEP3469744B1Method for coding by random acoustic signals and associated transmission method
Publication Date: 2020.05.27 COPSONIC
  • EP3469744B1 patent drawingFigure 1
  • EP3469744B1 patent drawingFigure 2
  • EP3469744B1 patent drawingFigure 3

AI summary

The invention relates to a method for coding information symbols of an alphabet in random acoustic signals. The coding dictionary is constructed in a heuristic manner by acquiring a set of random signals (110), by filtering same by means of the equivalent filter of the transmission channel, by selecting subsets of these signals (140), and, for each subset, by calculating the correlation matrix of the selected signals (160), the coding dictionary being constituted by the subassembly for which the correlation matrix most closely resembles a diagonal matrix (170-180). The invention also relates to a method for transmitting and receiving information symbols by means of acoustic signals.