Equivalences among Z2s -linear Hadamard codes
The Z2s -additive codes are subgroups of Z2s n, and can be seen as a generalization of linear codes over Z2 and Z4. A Z2s -linear Hadamard code is a binary Hadamard code which is the Gray map image of a Z2s -additive code. A partial classification of these codes by using the dimension of the kernel...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2020 |
| País: | España |
| Institución: | Universitat Autònoma de Barcelona |
| Repositorio: | Dipòsit Digital de Documents de la UAB |
| Idioma: | inglés |
| OAI Identifier: | oai:ddd.uab.cat:239897 |
| Acceso en línea: | https://ddd.uab.cat/record/239897 https://dx.doi.org/urn:doi:10.1016/j.disc.2019.111721 |
| Access Level: | acceso abierto |
| Palabra clave: | Classification Gray map Hadamard code Kernel Rank Z-additive code Theoretical Computer Science Discrete Mathematics and Combinatorics |
| Sumario: | The Z2s -additive codes are subgroups of Z2s n, and can be seen as a generalization of linear codes over Z2 and Z4. A Z2s -linear Hadamard code is a binary Hadamard code which is the Gray map image of a Z2s -additive code. A partial classification of these codes by using the dimension of the kernel is known. In this paper, we establish that some Z2s -linear Hadamard codes of length 2t are equivalent, once t is fixed. This allows us to improve the known upper bounds for the number of such nonequivalent codes. Moreover, up to t=11, this new upper bound coincides with a known lower bound (based on the rank and dimension of the kernel). Finally, when we focus on s∈{2,3}, the full classification of the Z2s -linear Hadamard codes of length 2t is established by giving the exact number of such codes. |
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