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 \(L \times L\):
where \(l=0,\ldots,L-1\) 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.
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. Birkhäuser, Boston, 1998.