On cyclic self-dual codes
We investigate cyclic self-dual codes over F(2)(r). We give a decomposition of a repeated-root cyclic codes over F(p)(r). The decomposition is used to analyze cyclic self-dual codes over F(2)(r). We obtain a necessary and sufficient condition for the existence of nontrivial cyclic self-dual codes over F(2)(r), and prove that all cyclic self-dual codes over F(2)(r) are Type I. Finally we classify cyclic self-dual codes of some lengths over F(4), F(8), and F(16).
self-dual codes cyclic codes generator polynomial