The adaptation of constrained codes to new channel input restrictions

The authors present several theorems and corollaries relating characteristic equations and values of channel capacity of some constrained sequences with different sets of input restrictions. These results provide with new characteristic equations for some classes of constrained sequences which can be used for enumeration of these sequences. It also becomes possible to find previously unknown values of channel capacity for some sequences by using tables which were calculated for other sequences. Code transformation algorithms which are systematic and easy to apply are presented with which a code, designed for use on a previously studied constrained channel, can be transformed to a new code with different constraints. This precludes the necessity of applying complex code synthesis algorithms to the new class of constraints