Block codes for a class of constrained noiseless channels

A class of discrete noiseless channels having upper and lower bounds on the separation between adjacent nonzero input symbols is considered. Recursion relations are derived for determining the number of input sequences which satisfy the constraints for all block lengths, and the asymptotic information rate is calculated. Applications to compaction and synchronization are discussed. An optimal algebraic block coding scheme for such channels is developed. © 1971 Academic Press, Inc.