New bounds for codes over finite Frobenius rings

We give further results on the question of code optimality for linear codes over finite Frobenius rings for the homogeneous weight. This article improves on the existing Plotkin bound derived in an earlier paper (Greferath and O’Sullivan, Discr Math 289:11–24, 2004) and suggests a version of a Singleton bound. We also present some families of codes meeting these new bounds.