An upper bound on the covering radius as a function of the dual distance

P. Delsarte (1973) developed a method that gives an upper bound on the cardinality of a code as a function of its minimum distance. It is shown that, using a modification of that method, one gets an upper bound on the covering radius of a code as a function of its dual distance. As an interesting special case, the covering radius of the dual of a BCH code is considered.<
>