Chaotic Secure Communication by Event-Triggered Extended High-Gain Observers

Abstract

The chaotic secure communication issue is addressed in this research using event-triggered extended high-gain observers. The communication system is based on two-channel communication, in which the transmitter system transmits the output of the chaotic system in one channel and the encrypted message that is obscured by the states of the chaotic system in the second channel. An event-triggering mechanism is introduced for each channel to decide the irregular time instants to transmit out the signal such that the resource-demanding continuous communication is avoided. In the receiver system, two event-triggered extended high-gain observers are proposed respectively to recover the chaotic system's states and unknown nonlinear function simultaneously, as well as the continuous encrypted message signal, from intermittently received signals. Based on the estimated signals, the message signal is decrypted by the inverse function of the encryption function. Theoretical analysis demostrates that Zeno phenomenon is not present and that the signal estimate errors diminish quickly to the area around the origin. Finally, simulation experiments are offered to demonstrate how well the proposed strategy works.