How the right amount of noise can enhance weak signal detection
Input signal + noise (threshold shown as dashed line)
Detector output — 1 when signal crosses threshold
SNR vs Noise Amplitude (sweet spot = stochastic resonance)
Stochastic Resonance
Counter-intuitively, adding noise to a sub-threshold signal can help it be detected. Too little noise → no crossings; too much → all noise; just right → signal rides over threshold.
Output = 1 if (signal + noise) > θ
SNR peaks at optimal noise level
Found in: neurons, sensory systems,
electronic circuits, climate models