Spectral shaping codes with even length permutation sequences
Khmaies Ouahada, Hendrik Christoffel Ferreira · 2011
A new technique of designing spectral null codes with permutation sequences is presented. These new codes have nulls at sub-multiples of the frequency of the transmitted symbols and are also DC-free codes. The choice of the corresponding channel levels given to each transmitted symbols has guaranteed the elimination of the DC component at the lower frequencies and gave an advantage on the binary spectral null codes by being DC-free codes.