Patent Document ID: 7957967
Application ID: 11540153
Patent Flag: 1

Claim One:
1. A method for classifying an input signal, comprising: establishing a first signal model; obtaining an input signal; determining a time-frequency representation of the input signal; determining, by a processor, whether a harmonic is present in the time-frequency representation; initiating spectrogram template matching, using the first signal model, in response to determining that the harmonic is present; and forgoing spectrogram template matching when the harmonic is not present; where determining whether the harmonic is present comprises: determining a frequency range to scan; scanning the time-frequency representation over the frequency range; identifying local peaks in the frequency range that exceed neighboring spectrum values by more than a peak threshold; counting votes for the local peaks; determining a normalized vote ratio using an expected number of harmonics in the frequency range; and comparing the normalized vote ratio to a harmonic threshold.