Abstract: Detection of weak signals in heavy noise background based on stochastic resonance was studied via numerical calculation. The relations of the amplitude and the signaltonoise ratio of the output signals of a nonlinear bistable stochastic resonance system to the noise intensity were researched under the high frequency condition. The results of numerical simulation show that the noise is restrained intensively by the nonlinear bistable system. High frequency weak signals in heavy noise background can be detected clearly based on stochastic resonance. The time domain and the characteristic spectrum of the frequency domain of output signals is obtained by extracting the high frequency weak signals with filtering wave technique. By means of the linear filter, the time domain of output signals can be obtained clearly.

Key words: stochastic resonance, high frequency weak signal, digital filter