arXiv subjects

Hassan Ou-azzou

Publications and source records attributed to Hassan Ou-azzou.

5 recordsLinked to original sources

arXiv2026

Equivalence of Families of Polycyclic Codes over Finite Fields

We study the equivalence of families of polycyclic codes associated with polynomials of the form $x^n - a_{n-1}x^{n-1} - \ldots - a_1x - a_0$ over a finite field. We begin with the specific case of polycyclic codes associated with a trinomial $x^n - a_{\ell} x^{\ell} - a_0$ (for some $0< \ell <n$), which we refer to as \textit{$\ell$-trinomial codes}, after which we generalize our results to general polycyclic codes. We introduce an equivalence relation called \textit{$n$-equivalence}, which extends the known notion of $n$-equivalence for constacyclic codes \cite{Chen2014}. We compute the number of $n$-equivalence classes %, $ N_{(n,\ell)}$, for this relation and provide conditions under which two families of polycyclic (or $\ell$-trinomial) codes are equivalent. In particular, we prove that when $\gcd(n, n-\ell) = 1$, any $\ell$-trinomial code family is equivalent to a trinomial code family associated with the polynomial $x^n - x^{\ell} - 1$. Finally, we focus on $p^{\ell}$-trinomial codes of length $p^{\ell+r}$, where $p$ is the characteristic of $\mathbb{F}_q$ and $r$ an integer, and provide some examples as an application of the theory developed in this paper.

cs.IT↗

arXiv2026

Skew polycyclic over finite chain rings associated to trinomials

This work studies skew polycyclic codes over finite chain rings defined by central trinomials. For this class of codes, we investigate Hamming equivalence in the non-commutative (skew) setting. We introduce an equivalence relation on the defining trinomials and demonstrate that it admits a group-theoretic characterization in terms of a group of binomials equipped with the Schur multiplication. We determine the conditions under which skew polycyclic codes are Hamming equivalent to those defined by the specific trinomial $x^n-(x^\ell+1)$. This reduces the classification problem for these codes, up to Hamming equivalence, to a canonical case. Finally, we determine the size of the corresponding equivalence class using the decomposition of the unit group of the underlying chain ring.

cs.IT↗

arXiv2025

Bounds and Equivalence of Skew Polycyclic Codes over Finite Fields

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.

cs.IT↗

arXiv2025

On polycyclic linear and additive codes associated to a trinomial over a finite chain ring

In this paper, we investigate polycyclic codes associated with a trinomial of arbitrary degree $n$ over a finite chain ring $ R.$ We extend the concepts of $ n $-isometry and $ n $-equivalence known for constacyclic codes to this class of codes, providing a broader framework for their structural analysis. We describe the classes of $n$-equivalence and compute their number, significantly reducing the study of trinomial codes over $R$. Additionally, we examine the special case of trinomials of the form $ x^n - a_1x - a_0 \in R[x] $ and analyze their implications. Finally, we consider the extension of our results to certain trinomial additive codes over $ R.$

cs.IT↗

arXiv2023

On $(n,σ)-$equivalence relation between skew constacyclic codes

In this paper we generalize the notion of $n$-equivalence relation introduced by Chen et al. in \cite{Chen2014} to classify constacyclic codes of length $n$ over a finite field $\mathbb{F}_q$, where $q=p^r$ is a prime power, to the case of skew constacyclic codes without derivation. We call this relation $(n,σ)$-equivalence relation, where $n$ is the length of the code and $ σ$ is an automorphism of the finite field. We compute the number of $(n,σ)$-equivalence classes, and we give conditions on $ λ$ and $μ$ for which $(σ, λ)$-constacyclic codes and $(σ, λ)$-constacyclic codes are equivalent with respect to our $(n,σ)$-equivalence relation. Under some conditions on $n$ and $q$ we prove that skew constacyclic codes are equivalent to cyclic codes. We also prove that when $q$ is even and $σ$ is the Frobenius autmorphism, skew constacyclic codes of length $n$ are equivalent to cyclic codes when $\gcd(n,r)=1$. Finally we give some examples as applications of the theory developed here.

cs.IT↗