Modulation and demodulation for detecting weak periodic signal of stochastic resonance

Modulated stochastic resonance method which can detect weak periodic signals under strong noise in wide parameter conditions is proposed in this paper. The high frequency weak signal mixed with noise is modulated to a low frequency difference signal. The signal conforms to the adiabatic elimination theory. So when it acts on stochastic resonance system, the stochastic resonance can arise. If the low frequency signal is demodulated, the original high frequency weak signal mixed with noise can be relrieved. To deal with the unknown frequency mixed with noise, the frequency of modulate oscillator is changed continuously to achieve a suitable difference frequency signal for inputting to stochastic resonance system. According to the change of resonance spectral peak value, the unknown frequency can be found from the demodulated signal. The method is effective for future application.