ABSTRACT
Chaos theory is one of the most important achievements in nonlinear system research. Chaos dynamics are deterministic but extremely sensitive to initial conditions. Chaotic systems and their applications to secure communications have received a great deal of attention since Pecora and Carroll proposed a method to synchronize two identical chaotic systems (Pecora & Carroll 1990). The high unpredictability of chaotic signal is the most attractive feature of chaos based secure communication. Several types of synchronization have been considered in communication systems. The Active Passive Decomposition (APD) method was proposed by Kocarev and Parlitz (1995), it was known as one of the most versatile schemes, where the original autonomous system is rewritten as controlled system with the desired synchronization properties. Many of the proposed solutions focused on synchronization-based methods for parameter estimation (Shen & Wang 2008, Ge & Chen 2005), among others. In (Parltiz & Junge 1996), the parameters of a given dynamic model were estimated by minimizing the average synchronization error using a scalar time series.
