Chaotic Communication System with Symmetry-Based Modulation

Timur Karimov,Denis Butusov,Georgii Kolev,Ekaterina Rodionova,Vyacheslav Rybin

doi:10.3390/app11083698

Timur Karimov, Denis Butusov + Show 3 more

Open Access

https://doi.org/10.3390/app11083698

Copy DOI

Abstract

Communication systems based on chaotic synchronization are gaining interest in the area of secure and covert data transmission. In this paper, a novel digital communication technique based on a coherent chaotic data transmission approach is proposed. In general, this technique resembles the well-known approach based on the modulation of nonlinearity parameters. The key idea of this study is to modulate a signal by varying not the system parameter but the symmetry coefficient in discrete chaotic models obtained by the special numerical integration method. For this purpose, the self-adjoint semi-implicit integration method of order 2 is used to obtain discrete master and slave models of the considered chaotic oscillator. The experimental results explicitly show that, like during parameter modulation, transmitting and receiving oscillators may completely synchronize only if the symmetry coefficients are equal in both systems. The architecture of the communication system based on the proposed modulation is presented. The practical applicability of the approach is confirmed by transmitting a test binary sequence between the transmitter and receiver models and preliminary benchmarking of the obtained communication system. Since the symmetry coefficient modulation does not significantly impact the chaotic behavior of the transmitting digital system, its better suitability for covert messaging was experimentally confirmed by comparing it with the parameter modulation technique.

Highlights

Digital modulation is a widely used technique in modern communication systems, for example, in a direct down-conversion software-defined radio (DDC SDR) which is in high demand on today’s market [1]
We propose a new coherent chaotic transmission method by modulating the symmetry parameter of the finite-difference model of a continuous chaotic system, obtained by symmetric semi-implicit integration, which is used for chaotic waveform generation
The key results of the reported study can be summarized as follows: 1. The proposed novel digital communication method based on the synchronization of chaotic systems allows the transmission of binary-coded messages

Summary

Introduction

Digital modulation is a widely used technique in modern communication systems, for example, in a direct down-conversion software-defined radio (DDC SDR) which is in high demand on today’s market [1]. Digital modulation provides opportunities that are not possible for neither analog nor binary modulation. It allows using arbitrary carriers, such as ultra-wideband signals and, which is of particular interest, chaotic signals, as well as applying advanced digital signal processing algorithms. The idea of using chaotic oscillators to implement communication systems goes back to the discovery of the chaotic synchronization phenomenon. Cuomo et al published in 1993 [2], a secure communication system is proposed using based on two circuits implementing the Lorenz chaotic oscillator. The authors present two possible data transmission schemes: masking of the analog signal by chaotic signal, and bifurcation parameter modulation suitable for binary data transfer. This work stated the fundamental possibility of such type of communication. One of the first papers that used chaotic communication for the transmission of complex signals such as speech was published by the Saratov nonlinear dynamics team [4]

Methods

Results

Discussion

Conclusion