A Fuzzy-Model-Based Chaotic Synchronization and Its Implementation on a Secure Communication System

In this paper, a synchronization mechanism of a fuzzy-model-based chaotic system is proposed. It is then implemented on a secure communication system (SCS) for verifying its functions. The fuzzy controller is designed to guarantee master-slave synchronization to be achieved in a pre-specified convergence time. A hardware implementation with the synchronous control for the SCS is realized with a field-programmable gate array chip and a personal computer. The SCS consists of two main parts: 1) a transmitter, which contains the master system (i.e., chaotic carrier) with the input messages and 2) a receiver, which contains the slave system with the output messages. Based on the proposed synchronization method, the SCS can decrypt the output messages rapidly and correctly in the receiver in which the encrypted signals are generated by a combination of the input messages and the master system's states. It should be emphasized that since we can assign the convergence time in advance so that the user can know the suitable time for the master system to mix the input messages. Finally, the performance and merit of the proposed control scheme is exemplified by practical experiments.