Irreducible components of canonical diagrams for spectral null constraints at f = fsk/n are studied, where k and n are relatively prime integers with 0 /spl les/s k < n and fs is the symbol frequency. To identify systematically all irreducible components of the canonical diagrams for first - order spectral nulls at f, we give a set of channel symbol sequences specifying all of them. If n is a prime number, then each sequence in the set corresponds to exactly one irreducible component up to label-preserving graph isomorphism. We also give a set of channel symbol sequences specifying all irreducible components of canonical diagrams for second-order spectral nulls at dc (i.e., f = 0).
['Hiroshi Kamabe']
Irreducible components of canonical diagrams for spectral nulls