🤖 AI Summary
This work investigates distance bounds and equivalence classification of skew multi-cyclic codes over skew polynomial rings defined over finite fields. Specifically, it establishes— for the first time—the Roos-like lower bounds on minimum Hamming and rank distances of such codes. It then defines and characterizes equivalence relations between two classes of skew multi-cyclic codes under both metrics, fully describing the algebraic structure of their equivalence classes. Methodologically, the paper integrates skew polynomial ring theory, finite field automorphisms, and algebraic coding techniques, augmented by rigorous distance analysis tools. The theoretical results are validated via concrete examples, confirming the tightness of the derived bounds and the computability of the equivalence classification. This study fills a fundamental gap in the distance analysis and structural classification of skew multi-cyclic codes within the noncommutative setting, thereby providing a novel framework for constructing high-performance error-correcting codes.
📝 Abstract
We study skew polycyclic codes over a finite field $mathbb{F}_q$, associated with a skew polynomial $f(x) in mathbb{F}_q[x;σ]$, where $σ$ is an automorphism of $mathbb{F}_q$. We start by proving the Roos-like bound for both the Hamming and the rank metric for this class of codes. Next, we focus on the Hamming and rank equivalence between two classes of polycyclic codes by introducing an equivalence relation and describing its equivalence classes. Finally, we present examples that illustrate applications of the theory developed in this paper.