SPREADOP Spreading operator
Usage: h=spreadop(f,c);
SPREADOP(f,c) applies the operator with spreading function c to the
input f. c must be square.
SPREADOP(f,c) computes the following for c of size L xL:
L-1 L-1
h(l+1) = sum sum c(m+1,n+1)*exp(2*pi*i*l*m/L)*f(l-n+1)
n=0 m=0
where l=0,...,L-1 and l-n is computed modulo L.
The combined symbol of two spreading operators can be found by using
tconv. Consider two symbols c1 and c2 and define f1 and f2 by:
h = tconv(c1,c2)
f1 = spreadop(spreadop(f,c2),c1);
f2 = spreadop(f,h);
then f1 and f2 are equal.
References:
H. G. Feichtinger and W. Kozek. Operator quantization on LCA groups. In
H. G. Feichtinger and T. Strohmer, editors, Gabor Analysis and
Algorithms, chapter 7, pages 233--266. Birkhauser, Boston, 1998.
Url: http://ltfat.github.io/doc/operators/spreadop.html
See also: tconv, spreadfun, spreadinv, spreadadj.
Package: ltfat