On the linearity and classification of Z_p^s-linear generalized Hadamard codes

Zp^s-additive codes of length n are subgroups of (Zp^s)^n , and can be seen as a generalization of linear codes over Z2, Z4 , or Z2^s in general. A Zp^s-linear generalized Hadamard (GH) code is a GH code over Zp which is the image of a Zp^s-additive code by a generalized Gray map. In this paper, we...

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Detalles Bibliográficos
Autores: Bhunia, Dipak Kumar|||0000-0003-4852-8739, Fernández Córdoba, Cristina|||0000-0001-5880-144X, Villanueva, M|||0000-0001-6179-0833
Tipo de recurso: artículo
Fecha de publicación:2022
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:259780
Acceso en línea:https://ddd.uab.cat/record/259780
https://dx.doi.org/urn:doi:10.1007/s10623-022-01026-2
Access Level:acceso abierto
Palabra clave:Hadamard code
Gray map
Zp^s-linear code
Zp^s-additive code
Kernel
Classification
Descripción
Sumario:Zp^s-additive codes of length n are subgroups of (Zp^s)^n , and can be seen as a generalization of linear codes over Z2, Z4 , or Z2^s in general. A Zp^s-linear generalized Hadamard (GH) code is a GH code over Zp which is the image of a Zp^s-additive code by a generalized Gray map. In this paper, we generalize some known results for Zp^s-linear GH codes with p = 2 to any odd prime p. First, we show some results related to the generalized Carlet's Gray map. Then, by using an iterative construction of Zp^s -additive GH codes of type (n; t 1 , . . . , t s ), we show for which types the corresponding Zp^s-linear GH codes of length p^t are nonlinear over Zp .For these codes, we compute the kernel and its dimension, which allow us to give a partial classification. The obtained results for p ≥ 3 are different from the case with p = 2. Finally, the exact number of non-equivalent such codes is given for an infinite number of values of s, t, and any p ≥ 2; by using also the rank as an invariant in some specific cases.