Method and apparatus for cancelling periodic electrical interference

摘要

A system involving method and apparatus for cancelling a periodic electrical interference signal from a signal of interest is disclosed. The system of the invention creates an estimate of the periodic noise component in an electrical signal by sampling the electrical signal at intervals locked to the period of the source of the electrical interference signal. The system analyzes the sampled signal to isolate periodically repeating portions of the signal characteristic of noise. The system inverts the estimate of the noise component and constructs a continuous repeating waveform which is added to the electrical signal. The system does not eliminate transient features of the signal of interest, even when those transient features have frequency components which overlap with frequencies present in the electrical interference signal.