RESEACH ON CHAOTIC SYNCHRONIZATION IN COUPLED PHASE-LOCKED LOOPS

在这个项目中，我们研究了耦合混沌锁相环的相互同步。我们特别关注4和2相互耦合的锁相环。在模型方程的计算机模拟中，我们成功地实现了这些耦合混沌系统在强耦合情况下的同步。然而，在实际的电子电路实验中，虽然可以在一定时间内实现混沌同步，但同步会被偶尔的脉冲打断，即同步中断。因此，我们无法实现模拟混沌系统的鲁棒同步。然而，我们从非线性动力学的角度阐明了混沌爆发的机理，包括开关间歇和一种新型的间歇。进一步。利用有限位长的数字信号处理器研究了伪混沌的安全通信，并取得了一定的成功。作为未来的研究项目，我们的目标是利用数字信号处理器构建一个具有真实混沌的安全通信系统。这似乎是通过在电阻的最小位上添加模拟噪声来实现的。

In this project, we investigate mutual synchronization of coupled chaotic phase-locked loops. In particular, we focus our attention to 4 and 2 mutually coupled phase-locked loops. In computer simulation of the model equation, we succeeded in achieving synchronization of these coupled chaotic systems for strong coupling cases. However, in actual electronic circuit experiments, although chaos synchronization was possible for certain period, the synchronization was interrupted by occasional impulses meaning break of synchronization. As a result, we could not achieve robust synchronization of analog chaotic systems. However, we elucidated a mechanism of the chaotic burst including on-off intermittency and a new type of intermittency from the viewpoint of nonlinear dynamics. Further. we investigated secure communication with pseudo chaos using a finite bit length digital signal processor, and succeeded to some extent. As a future research project, we challenge to build a secure communication system with real chaos using a digital signal processor. This seems to be achieved by adding an analog noise to the least bit of the resistor.