Stochastic resonance in a linear system with signal-modulated noise

¹ State Key Laboratory for Laser Technology Huazhong University of Science and Technology - Wuhan 430074, PRC
² CCAST (World Laboratory) - P.O. Box 8730, Beijing 100080, PRC
³ Department of Physics, Huazhong University of Science and Technology Wuhan 430074, PRC

Received: 26 August 2002
Accepted: 12 December 2002

Abstract

The stochastic resonance characteristics of a linear system driven by a signal-modulated noise and an unmodulated noise are studied. Both the signal-modulated noise and the unmodulated noise are additive in nature and they are correlated. Our study shows that the correlation between the two noises leads to stochastic resonance. An exact analytic expression of the signal-to-noise ratio R is obtained. Based on it, some characteristic features of stochastic resonance are revealed. In the final analysis, the existence of a resonance peak of R vs. noise intensity is a noise correlation effect. On the other hand, the existence of a resonance peak of R vs. noise correlation time τ exhibits a signal-modulated effect of noise. It should be emphasized that the resonance peak of the R-τ curve exists even for uncorrelated noises. This is very different from the case of dependence on the noise strengths.