Two-weight codes, graphs and orthogonal arrays

Two-weight codes, graphs and orthogonal arrays

We investigate properties of two-weight codes over finite Frobenius rings, giving constructions for the modular case. A δ-modular code [15] is characterized as having a generator matrix where each column g appears with multiplicity δ|gR×| for some δ ∈ Q. Generalizing [10] and [5], we show that the additive group of a two-weight code satisfying certain constraint equations (and in particular a m...

Ring geometries, two-weight codes, and strongly regular graphs

It is known that a linear two-weight code C over a finite field Fq corresponds both to a multiset in a projective space over Fq that meets every hyperplane in either a or b points for some integers a < b , and to a strongly regular graph whose vertices may be identified with the codewords of C . Here we extend this classical result to the case of a ring-linear code with exactly two nonzero homo...

Weight enumerators of self-orthogonal codes

Two-weight and three-weight codes from trace codes over

We construct an infinite family of two-Lee-weight and three-Lee-weight codes over the non-chain ring Fp+uFp+ vFp+uvFp, where u 2 = 0, v = 0, uv = vu. These codes are defined as trace codes. They have the algebraic structure of abelian codes. Their Lee weight distribution is computed by using Gauss sums. With a linear Gray map, we obtain a class of abelian three-weight codes and two-weight codes...

ℤ4-codes and their Gray map images as orthogonal arrays

A classic result of Delsarte connects the strength (as orthogonal array) of a linear code with the minimum weight of its dual: the former is one less than the latter. Since the paper of Hammons et al., there is a lot of interest in codes over rings, especially in codes over Z4 and their (usually non-linear) binary Gray map images. We show that Delsarte’s observation extends to codes over arbitr...