Quantum maximum-distance-separable (MDS) codes are an important class of quantum codes. In this paper, using constacyclic codes and Hermitain construction, we construct some new quantum MDS codes of the form q = 2am + t, n = q 2 +1 a . Most of these quantum MDS codes are new in the sense that their parameters are not covered be the codes available in the literature.

We give the structure of λ-constacyclic codes of length pm over R = Fpr +uFpr + . . .+uFpr with λ ∈ F ∗ pr . We also give the structure of λ-constacyclic codes of length pm with λ = α1 + uα2 + . . .+ u αe−1, where α1, α2 6= 0 and study the self-duality of these codes.

For any different odd primes l and p, structure of constacyclic codes of length 2lp over a finite field Fq of characteritic p and their duals is established in term of their generator polynomials. Among other results, all linear complimentary dual and self-dual constacyclic codes of length 2lp over Fq are obtained.

In this paper we introduce the notion of λ-constacyclic codes over finite rings R for arbitrary element λ R. We study non-invertible-element constacyclic (NIE-constacyclic codes) principal ideal (PIRs). determine algebraic structures all NIE-constacyclic chain rings, give unique form sets defining polynomials and obtain their minimum Hamming distances. A general duals is also provided. particul...

An equivalence relation called isometry is introduced to classify constacyclic codes over a finite field; the polynomial generators of constacyclic codes of length lp are characterized, where p is the characteristic of the finite field and l is a prime different from p.

Abstract We study the structure of constacyclic codes of length ps over the ring Fpk + uFpk + · · · + um−1Fpk in terms of ideals in the quotient ring (Fpk + uFpk + · · · + um−1Fpk)[x]/〈xp s − λ〉, where λ is a unit element in Fpk + uFpk + · · · + um−1Fpk . In particular, we complete a structural classification of constacyclic codes of length ps over Fpk + uFpk and determine their minimum Hamming...

Let $\mathbb{F}_p$ be a finite field and $u$ be an indeterminate. This article studies $(1-2u^2)$-constacyclic codes over the ring $\mathbb{F}_p+u\mathbb{F}_p+u^2\mathbb{F}_p$, where $u^3=u$. We describe generator polynomials of this kind of codes and investigate the structural properties of these codes by a decomposition theorem.

Let m, e be positive integers, p a prime number, Fpm be a finite field of p elements and R = Fpm [u]/〈u 〉 which is a finite chain ring. For any ω ∈ R and positive integers k, n satisfying gcd(p, n) = 1, we prove that any (1+ωu)-constacyclic code of length pn over R is monomially equivalent to a matrix-product code of a nested sequence of p cyclic codes with length n over R and a p × p matrix Ap...