THE CEPSTRUM OF POLE-ZERO FILTERS
Consider a minimum phase system with a rational transfer function:
Taking the complex logarithm:
Taking an inverse z-transform:
It is easy to see that the cepstrum is a decaying function
of time (compact). Why is this desirable?
Recalling that the real cepstrum can be computed
from the even part of the complex cepstrum,
the complex cepstrum can also be easily determined from the
real cepstrum, c(n), as follows:
