Patent ID: 7027980

Claim:
A system of modeling a signal in accordance with a computer program stored in at least one of a memory, an application specific integrated circuit, a digital signal processor and a field programmable gate array, comprising: a) an input for receiving the signal; b) a harmonic analyzer operable to identify a plurality of harmonic magnitudes and a plurality of harmonic frequencies of the signal; c) a first interpolator, responsive to the plurality of harmonic magnitudes and operable to produce a first plurality of spectral magnitudes at a set of fixed frequencies; d) an inverse transformer, responsive to the first plurality of spectral magnitudes or to a next plurality of spectral magnitudes and operable to produce a pseudo auto-correlation sequence therefrom; e) a linear prediction analyzer, operable to calculate a set of linear prediction coefficients from the pseudo auto-correlation sequence; f) a first spectrum calculator, responsive to the set of linear prediction coefficients and operable to produce a plurality of model harmonic magnitudes therefrom; g) a scale calculator operable to calculate a first set of scale factors as the ratio of the harmonic magnitudes to the model harmonic magnitudes; h) a second interpolator, operable to interpolate the first set of scale factors to obtain a second set of scale factors at the set of fixed frequencies; i) a second spectrum calculator, operable to calculate model spectral magnitudes at the set of fixed frequencies by sampling the spectral envelope defined by the linear prediction coefficients at the set of fixed frequencies; j) a multiplier, operable to multiply the model spectral magnitudes at the set of fixed frequencies by the second set of scale factors to obtain the next plurality of spectral magnitudes; and k) an output for outputting the linear prediction coefficients, wherein the inverse transformer is operable to inverse transform the next plurality of spectral macinitudes to obtain a new pseudo auto-correlation sequence and wherein the linear prediction analyzer is operable to calculate new linear prediction coefficients from the new pseudo auto-correlation sequence and wherein the signal is modeled by the new linear prediction coefficients.