NAC-based Synchronisation and Anti-synchronisation Between Hyperchaotic and Chaotic Systems, Its Analogue Circuit Design and Application

Abstract

ABSTRACTThe objectives of this paper are synchronisation and anti-synchronisation between a hyperchaotic and a chaotic systems using nonlinear active control (NAC) scheme, its analogue circuit design and application to secure communication. Hyperchaotic Lorenz–Stenflo system is used as a master and the chaotic (a hyperchaotic system in its chaotic state) Chen system is used as a slave in this paper. Chaotic slave system is controlled to make it synchronised and anti-synchronised with the hyperchaotic master system by designing a modified NAC law via suitable forcing. Proposed scheme is applied in communication to ensure more security of the message signal through hyperchaotic masking. The MATLAB environment is used to simulate synchronisation, anti-synchronisation of the proposed hyperchaotic-chaotic pair using the modified NAC law and its application to secure communication application. The simulation results reflect the successful achievement of the objectives. Further, analogue circuit designs of the hyperchaotic Lorenz–Stenflo, the chaotic Chen systems as well as their synchronisation and anti-synchronisation of proposed pair using modified NAC are presented in this paper and realised in NI Multisim. NI Multisim circuit realisation results validate the simulation results and the fulfilment of the desired objectives of the paper.