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NASA Administration Appointment Lewis Research Center |
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The observation by Pecora and Carrol that two chaotic systems can be sychronized has generated tremendous interest in transmitting information from one location to another using a wideband chaotic signal. The transmitted waveform resembles random noise. The receiver contains a second chaotic system that produces an identical chaotic signal but without the encoded message, enabling the transmitted message to be extracted from the chaos. The scheme for communications relies on two suprising properties of chaotic systems. First, message recovery relies on the ability of coupled chaotic systems to synchronize or produce identical chaotic behavior. Second, message encoding utilizes chaos control or applying small perturbations to stabilize one of the many unstable periodic behaviors typically displaced by chaotic systems. A chaotic communication system may possess advantages of privacy and efficiency over conventional systems. The potential for practical application drives the current widespread interest in understanding fundamentally chaos control and synchronization. To that end, we would like to investigate several systems, such as Josephson Junctions, Chua's circuit (low frequency oscillator), Colpitts circuit (high frequency oscillator) and new class of chaotic circuit by Sprott, driven by a sinusoidal perturbation. In many situations controlling chaotic systems by periodic forcing is useful in the applications as reported in references which includes synchronization of two chaotic systems. Thus, determining the convenient driving parameters (usually amplitude and frequencies) is relevant to improve the desired control or oscilliation phase-locking in the considered systems. Furthermore, investigating the dependence of this effect, or other bifurcation phenomena commonly observed in such driven systems, on the required control driving parameters, is also convenient. Electronic nonlinear circuits are particularly useful to investigate these nonlinear phenomena, as the mentioned oscillation phase-locking. In fact, these sytems are experimentally easy to build, usually with very low noise levels, and their characteristic dynamics are well modeled by differential equations. This new field of nonlinear communication theory promises to develop into a new paradigm offering a general information transmission technique, useful to both electronic and optical media, which should find wide applications in civil and military communications infrastructures. Dr. Andro's Visit to ECSU Return to NRTS | |