Higher order stochastic resonance in a level-crossing detector

Abstract

We investigate stochastic resonance in a simple level-crossing detector at the base frequency, as well as the higher harmonics, of a periodic stimulus. Using quadratic approximations, we observe a stochastic resonance phenomenon with two maxima (in the presence of white Gaussian background noise) in the first harmonic at the output power spectral density of the system. That means that there is an optimal strength of the input noise, where the signal transfer is the most linear, as the first harmonic is concerned. This unique feature of this system cannot be found at the fundamental harmonic in the output. The theoretical results are confirmed by numerical simulations. This system is a good candidate for use in simple models of neurons, and other (nonlinear) signal detection systems.