Noise assisted weak signal detection using a sinusoid-crossing analog-to-digital converter

Abstract

We utilize noise to characterize signals that have amplitude values that are lesser than the detection limit of sinusoid crossing based analog-to-digital converter. The noise functions as an additive signal that boosts the power of weak signals above the threshold level. Experimental verification was done on synthetic sinusoid signals from a function generator and an electronic implementation of the sinusoid crossing technique with an effective dynamic range of 2¹¹ and a sampling frequency of 23420 Hz. Signals added with noise achieve improved signal-to-noise ratio with optimum noise variance that is observed at a σ ~ 0.007 V, which is close to the detection limit of the system.