An adaptive IIR phase measurement structure for estimation of multiple sinusoids

The phase measurement (PM) method, which makes use of the difference between the input and output of a tunable infinite impulse response (ITR) bandpass filter, is used for adaptive estimation of the fundamental pitch of a signal composed of multiple sinusoids. The estimator has the useful characteristic of ordering the detected frequency components independently of the initial starting values of the section coefficients. In addition to frequency estimation, the amplitude of each component can be extracted from the corresponding bandpass output, which is useful in applications where components envelopes are need for re-synthesis algorithms. The performance of the PM method is compared with that of the recursive least-mean-square method