S. Nordebo et I. Claesson, MINIMUM NORM DESIGN OF 2-DIMENSIONAL WEIGHTED CHEBYSHEV FIR FILTERS, IEEE transactions on circuits and systems. 2, Analog and digital signal processing, 44(3), 1997, pp. 251-253
The weighted Chebyshev design of two-dimensional FIR filters is in gen
eral not unique since the Haar condition is not generally satisfied. H
owever, for a design on a discrete frequency domain, the Haar conditio
n might be fulfilled. The question of uniqueness is, however, rather e
xtensive to investigate. It is therefore desirable to define some simp
le additional constraints to the Chebyshev design in order to obtain a
unique solution. The weighted Chebyshev solution of minimum Euclidean
filter weight norm is always unique, and represents a sensible additi
onal constraint since it implies minimum white noise amplification. Th
is unique Chebyshev solution can always be obtained by using an effici
ent quadratic programming formulation with a strictly convex objective
function and linear constraints. An example where a conventional Cheb
yshev solution is nonunique is discussed in the brief.