METHOD OF REMOVING DISPERSIVE SINUSOIDAL NOISE

摘要

An analog signal, for example an E.C.G signal carrying a mains hum component is sampled by a sampler 3 and the sampler applied to a difference circuit 4. A feedback circuit from the output of circuit 4 to its other input includes a programmable gain amplifier 7 and a discrete sine wave generator 8. The sine wave generator operates at the frequency of the mains hum component and has its amplitude and phase controlled by the output of amplifier. The output from generator 8 controls the gain of amplifier 7 and is applied to circuit 4 to cancel the hum component of the samples.