Hermitian Self-dual Generalized Reed-Solomon Codes
Chun'e Zhao, Wenping Ma
TL;DR
The paper solves the long-standing problem of characterizing Hermitian self-dual generalized Reed-Solomon codes over $\mathbb{F}_{q^2}$. It proves that no such codes exist for length $n> q+1$ and, for $n\le q+1$, there are exactly two classes. It then provides two explicit construction methods corresponding to these classes, thereby completing both existence and constructive aspects. The results have practical implications for designing Hermitian self-dual MDS codes via GRS codes, with direct impact on coding theory applications where duality properties are crucial.
Abstract
Maximum Distance Separable (MDS) self-dual codes are of significant theoretical and practical importance. Generalized Reed-Solomon (GRS) codes are the most prominent MDS codes. Correspondingly there have been many research on constructions of Euclidean self-dual MDS codes by using GRS codes. However, the study on Hermitian self-dual GRS codes is relatively limited. Since Hermitian self-dual GRS codes do not exist for $n>q+1$, this paper is devoted to an investigation of GRS codes in the case where $n\le q+1$. First, we prove that when $n\leq q+1$, there are only two classes of Hermitian self-dual GRS codes, confirming the conjecture in [13] and providing its proof simultaneously. Second, we present two explicit construction methods. Thus, the existence and construction of Hermitian self-dual GRS codes are fully solved.
