Chaotic Sequence Generator Using Hidden Markov Model Detection

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Solution Overview

Problem

Current chaos-based communications systems suffer from low throughput due to analog chaos generator circuits that drift over time, requiring constant synchronization of transmitter and receiver, and non-coherent systems have reduced throughput and error rates.

Innovation Solution

A coherent chaotic spread-spectrum communication system that generates statistically orthogonal chaotic sequences for data modulation, using algorithms like bijective functions and fractal evolution transformations, and employs a Hidden Markov Model for demodulation to maintain synchronization without constant state information transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If analog chaos generator circuits are used to generate chaotic signals, then chaotic properties are achieved, but drift over time occurs requiring constant synchronization

Engineering Contradiction:
Improvechaotic signal stabilityVSAvoidsynchronization time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent replaces analog chaos generator circuits with a digital chaos generator implemented as a finite state machine. This substitution eliminates the drift problem inherent in analog circuits by using discrete digital logic elements (D-flip-flops, XOR gates, AND gates) that maintain stable chaotic sequences without temporal degradation, thereby resolving the contradiction between signal stability and synchronization requirements.

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

2Reliability

If state information is constantly transferred to maintain synchronization, then transmitter and receiver remain synchronized, but throughput decreases

Engineering Contradiction:
Improvesynchronization accuracyVSAvoiddata throughput
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent implements self-synchronization by designing the receiver's finite state machine to independently regenerate the same chaotic sequence as the transmitter using identical initial conditions and the same chaotic algorithm. This self-service mechanism eliminates the need for continuous state information transfer, as the receiver autonomously maintains synchronization, thereby resolving the contradiction between synchronization accuracy and data throughput.

Inventive Principle:
Principle #25Self-service

3Stability of the object's composition

If digital logic is used to generate chaotic sequences, then drift is eliminated, but implementation complexity increases due to precision requirements

Engineering Contradiction:
Improvechaotic sequence stabilityVSAvoiddigital circuit complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent transforms the chaotic sequence generation from requiring high-precision arithmetic operations to using discrete digital logic states. By changing the parameter domain from continuous analog values to discrete digital states (0 and 1), the system achieves stable chaotic sequences without drift while simplifying the implementation to basic logic gates and flip-flops, thereby resolving the contradiction between stability and complexity.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2365653B1Hidden markov model detection for spread spectrum waveforms
Publication Date: 2014.05.21 HARRIS CORP
  • EP2365653B1 patent drawingFigure 1
  • EP2365653B1 patent drawingFigure 2
  • EP2365653B1 patent drawingFigure 3

AI summary

Systems and methods for processing a data signal in a communications system. The methods involve generating a first chaotic sequence at a transmitter. The methods also involve performing first basis function algorithms using the first chaotic sequence to generate first statistically orthogonal chaotic sequences. At least one sequence is selected from the first statistically orthogonal chaotic sequences for combining with a first data signal. The selected sequence is combined with a second data signal to obtain a modulated chaotic communication signal. The modulated chaotic communication signal is transmitted to a receiver. At the receiver, the received modulated chaotic communication signal is processed to obtain data therefrom. Notably, the signal processing generally involves performing a deterministic process (e.g., a Hidden Markov Model deterministic process).