I. Introduction
Exploiting chaotic signals in communications has received significant attention in recent years [1]. The main premise in these studies is that broad-band signals generated by simple deterministic systems with chaotic dynamics can potentially replace pseudo-random carrier signals widely used in modern spread-spectrum communication systems (see for example, [2]). These pseudo-random sequences are generated by complex digital signal processors, and yet they are periodic due to the digital nature of the processor. In contrast, even a simple nonlinear circuit with very few off-the-shelf electronic components is capable of generating a very complex set of chaotic signals. The simplicity of chaos generators and the rich structure of chaotic signals are the two most attractive features of deterministic chaos that have caused a significant interest in possible utilization of chaos in communication.