Self-dual 2-quasi-cyclic Codes and Dihedral Codes
Abstract
We characterize the structure of 2-quasi-cyclic codes over a finite field F by the so-called Goursat Lemma. With the characterization, we exhibit a necessary and sufficient condition for a 2-quasi-cyclic code being a dihedral code. And we obtain a necessary and sufficient condition for a self-dual 2-quasi-cyclic code being a dihedral code (if charF = 2), or a consta-dihedral code (if charF odd). As a consequence, any self-dual 2-quasi-cyclic code generated by one element must be (consta-)dihedral. In particular, any self-dual double circulant code must be (consta-)dihedral. Also, we show a necessary and sufficient condition that the three classes (the self-dual double circulant codes, the self-dual 2-quasi-cyclic codes, and the self-dual (consta-)dihedral codes) are coincide each other.
Keywords
Cite
@article{arxiv.2201.01497,
title = {Self-dual 2-quasi-cyclic Codes and Dihedral Codes},
author = {Yun Fan and Yuchang Zhang},
journal= {arXiv preprint arXiv:2201.01497},
year = {2022}
}