This paper provides a generalization of certain classical Fourier convergen
ce and asymptotic Toeplitz matrix properties to the case where the underlyi
ng orthonormal basis is not the conventional trigonometric one but rather a
rational generalization which encompasses the trigonometric one as a speci
al case. These generalized Fourier and Toeplitz results have particular app
lication in dynamic system estimation theory. Specifically, the results all
ow a unified treatment of the accuracy of least-squares system estimation u
sing a range of model structures, including those that allow the inclusion
of prior knowledge of system dynamics via the specification of fixed pole o
r zero locations.