Upper bounds and Hamming spheres under the DC-constraint
Helio Waldman, Eduardo Nisenbaum · 2002
Upper Hamming bounds are derived for the asymptotic rates R of DC-free binary codes with imbalances 3, 4 and 5. For large enough fractional distances /spl delta/, we derive an improved Plotkin bound, given by the straight line that contains the cutoff point (R=0, /spl delta/=.5) and is tangent to the Hamming bound.>