Linear prediction
Another well known method for converting the least-damped modes into
parametric form is Linear Predictive Coding (LP) followed by polynomial
factorization to obtain resonator poles. LP is particularly good at
fitting spectral peaks due to the nature of the error criterion it minimizes
[428]. The poles closest to the unit circle in the
plane can be chosen for the ``ringy'' part of the resonator. It is well
known that when using techniques like LP to model spectral peaks for
extraction, orders substantially higher than twice the number of spectral
peaks should be used. The extra degrees of freedom in the LP fit give more
poles for modeling spectral detail other than the peaks, allowing the poles
modeling the peaks to fit them with less distraction. On the other hand,
if the order chosen is too high, sometimes more than two poles will home
in on the same peak. In some cases, this may be appropriate since the
body resonances are not necessary resolvable so as to separate the peaks,
especially at high frequencies.
Next Section:
Sinusoidal modeling
Previous Section:
Weighted digital filter design