Research On Communication Schemes With Chaotic Parameter Modulation

Chaotic signals are irregular, aperiodic, noise-like, uncorrelated, broad frequency spectrum, very sensitive to initial conditions. These properties mentioned above make chaos apply in secure communication particularly. Chaos parameter modulation communication has satisfactory confidentiality with the entire range of frequency spectrum to conceal message. At present, there are few schemes of chaotic modulation and demodulation based on time-varying parameter, and much less on practical circuit communication system.In this paper, the contents of the study are mainly focused on designing appropriate modulation and demodulation methods to restore the message signal concealed in the chaos signals based on chaos synchronization. The main contributions are as follows: With chaos synchronization very sensitive to parameters, a digital communication method is proposed by designing a demodulating method to restore information signal. With a nonlinear low-pass filter, a method of modulation and demodulation is discussed in self-synchronizing chaotic communication systems. Based on adaptive control method, a controller is designed to control receiver and transmitter chaotic systems to synchronize, and design appropriate parameter estimation function so that states of parameters in receiver can synchronously track to all states of the parameters in transmitter. By estimating the parameters in receiver, information signals are demodulated. In this paper, Single parameter modulation and multi-parameter modulation for secure communication are discussed. All the methods are proved to be effective by numerical simulations. Then, a secure communication circuit is designed. Through a circuit simulation, the feasibility of the communication scheme is verified.