On the covering radius of an unrestricted code as a function of the rate and dual distance Original Research Article

We present a uniform approach towards deriving upper bounds on the covering radius of a code as a function of its dual distance structure and its cardinality. We show that the bounds obtained previously by Delsarte, Helleseth et al., Tietäväinen, resp. Solé and Stokes follow as special cases. Moreover, we obtain an asymptotic improvement of these bounds using Chebyshev polynomials.