On existence of good self-dual quasicyclic codes

This paper describes the existence of good self-dual quasicyclic codes. In this paper, with the assumption that there are infinite primes p for which 2 is primitive, we prove that there exist classes of self-dual 2p-quasicyclic codes and Type II 8p-quasicyclic codes of length respectively 2p² and 8p² which asymptotically meet the Gilbert-Varshamov bound.