Patent ID: 7307700

Claim:
A method for processing a signal, the method comprising: sampling a sinusoidal signal over a finite period of time at a plurality of subintervals; pre-processing the plurality of sampled subinterval signals, wherein pre-processing includes: filtering the plurality of sampled subinterval signals; creating a zero-padded sample by adding to the sampled subinterval signal a plurality of sample points that are all zeroes; and rotating the zero-padded sample by a predetermined amount such that a first part of the zero-padded sample that is near a midpoint of the sinusoidal signal is placed at a first end of a sample window and a second part of the zero-padded sample that is near the midpoint of the sinusoidal signal is placed at a second end of the sample window; performing a Fourier transform on the plurality of pre-processed sampled subinterval signals; extracting phases of the plurality of pre-processed sampled subinterval signals from the Fourier transform; and determining a parameter indicative of frequency of the sinusoidal signal from the slope of the phases of the plurality of pre-processes sampled subinterval signals.