NOISE-ENHANCED HETERODYNING IN BISTABLE SYSTEMS

A new form of heterodyning is reported in which a heterodyne signal at the difference frequency between an input signal and a reference signal can be enhanced by adding noise. The underlying mechanism is closely related to that of stochastic resonance. The dependences of the heterodyne signal and the signal-to-noise ratio on the amplitudes and frequencies of the input and reference signals have been investigated. Noise-induced enhancement of the heterodyning has been demonstrated both for white noise and for high-frequency noise (with the power spectrum centered at the frequency of the reference signal) added at the input.