  Identification of fractional order systems is considered from an algebraic
point of view. It allows for a simultaneous estimation of model parameters and
fractional (or integer) orders from input and output data. It is exact in that
no approximations are required. Using Mikusinski's operational calculus,
algebraic manipulations are performed on the operational representation of the
system. The unknown parameters and (fractional) orders are calculated solely
from convolutions of known signals. A generalized Voigt model describing a
viscoelastic material is used to illustrate the approach.
