Nonlinear Filtering of Chaotic Signal Based on Stochastic Resonance Effect

Abstract

Nonlinear radio engineering systems are promising. There is a tendency to use complex broadband signals to transmit information. The ratio of signal power to noise power is reduced. When using the stochastic resonance phenomenon in a bistable nonlinear dynamic system, conditions are created for amplifying a weak information signal as a result of its interaction with noise. Such a nonlinear filter contains a bistable system-a Schmitt trigger and a linear filter. Filtering occurs due to the stochastic resonance effect. The signal at the output of a nonlinear system is amplified at some optimal noise intensity. The model of a real information signal is a chaotic oscillation. Chaotic oscillations are generated by a nonlinear dynamic system. From the modern point of view, chaotic and stochastic fluctuations are determined by the value of the fractal dimension. There are theoretical studies of nonlinear dynamic systems with added noise. There are no applied studies of radio engineering systems in circuit modeling programs. Problems of processing chaotic signals in receivers have not been sufficiently investigated. In this case, the transmitter signal undergoes changes in the communication channel due to the filtering properties of the channel and the addition of interference to the signal. It is not enough to consider the phenomenon of stochastic resonance in relation to filtering an additive mixture of a harmonic signal and noise. The results of an experimental study of a nonlinear filter in the Multisim program are presented.