Stochastic Resonance In Digital Signal Processing Applications

Stochastic resonance has attracted the attentions in many fields of science in recent decades, but it is a new method and theory in signal processing. In context of signal processing, for signal transmission by nonlinear systems, stochastic resonance is commonly described as an increase hi the signal-to-noise ratio (SNR) at the output, which is obtained through an increase of noise level or tuning system parameters.We mainly researui uic application of the stochastic resonance in the digital signal transmission, where the adopted method is not increasing noise density, but tuning the system parameters to enhance the SNR or channel capacity. From Langevin Equation, the stochastic resonance characteristics of bistable system were investigated, including the probability density function and other character numbers. We discussed detailedly the application of parameter-induced stochastic resonance in binary baseband pulse amplitude modulated (PAM) signal transmission. The system's measurements: bit error rate and channel capacity were deduced. The numerical simulation demonstrated our theoretical analyses.In addition, this paper discusses the application of the parameter-induced stochastic resonance in the M-ary PAM signal transmission, and explains the mechanism to stochastic resonance in a new view. We found that the single well is able to distinguish different signal levels, based on which the theory for M-ary PAM signal transmission via parameter-induced stochastic resonance was briefly developed. The error code rate of M-ary PAM signal was obtained. The numerical simulations show that this research direction has a good project in communication.