Diameter perfect codes form a natural generalization for codes. They are based on the code-anticode bound which generalizes sphere-packing bound. The was proved by Delsarte distance-regular graphs and it holds some other metrics too. In this paper we prove non-binary constant-weight with Hamming metric characterize diameter maximum size anticodes these We distinguish between six families of fou...

The parameters of a linear block code over the finite field Fq of length n, dimension k and minimum distance d will be denoted by [n, k, d]q or [n, k, d]. The quotient k/n is called the information rate and denoted by R = k/n and the relative minimum distance d/n is denoted by δ. A sequence of codes (Cm|m ∈ N) with parameters [nm, km, dm] over a fixed finite field Fq is called asymptotically go...

There is a classical lower bound on the dimension of a binary Goppa code. We survey results on some specific codes whose dimension exceeds this bound, and prove two conjectures on the true dimension of two classes of such codes.

Equidistant constant weight codes are studied in this paper. The dual distance distribution of equidistant constant weight codes is investigated and used to obtain upper bounds on the size of such codes as well as equidistant codes in general. ? 2003 Elsevier Science B.V. All rights reserved.