Constructions and properties of block codes for partial-response channels

We report on block-coding techniques for partial-response II. PRELIMINARY channels with transfer function (1 F Dm), m = 1,2, . . We consider various constructions of block codes with prescribed min imum Euclidean Let u = (x1,... ,un) andv = (VI,..., un) be two n-tuples over distance. Upper and lower bounds to the size of a code with min imum @ = {-l,l}. Define the difference vector e = (el,...,e,+,) for squared Euclidean distance greater than unity are furnished. A table the PR channel with transfer function (1 + aDm), m = 1,2,..., is presented of cardinalities of codes of small length with prescribed min imum squared Euclidean distance. and a = ~1, as