Upper Bound on the Efficiency of dc-Constrained Codes
Ta-Mu Chien · Bell System Technical Journal · 1970
We derive the limiting efficiencies of dc-constrained codes. Given bounds on the running digital sum (RDS), the best possible coding efficiency η, for a K-ary transmission alphabet, is η = log2λmax/log2K, where λmaxis the largest eigenvalue of a matrix which represents the transitions of the allowable states of RDS. Numerical results are presented for the three special cases of binary, ternary and quaternary alphabets.