Signal-to-noise ratio gain by stochastic resonance in a bistable system

It was shown recently that the signal-to-noise ratio (SNR) could be improve d by stochastic resonance (SR) in certain monostable systems and certain sy stems with monotonous nonlinearity working in the nonlinear response (NLR) regime. Here we demonstrate that a simple bistable system driven by periodi c pulse train and band-limited Gaussian white noise can also provide an SNR gain. We show the reasons why SNR gain had not been found in double well p otential systems, despite strong efforts made during the last 15 years. (C) 2000 Elsevier Science Ltd. All rights reserved.