Z2Z4-additive codes

Abstract

Altres ajuts: UAB PNL2006-13The Combinatoric, Coding and Security Group (CCSG) is a research group in the Department of Information and Communications Engineering (DEIC) at the Universitat Aut'onoma de Barcelona (UAB). The research group CCSG has been uninterruptedly working since 1987 in several projects and research activities on Information Theory, Communications, Coding Theory, Source Coding, Cryptography, Electronic Voting, Network Coding, etc. The members of the group have been producing mainly results on optimal coding. Specifically, the research has been focused on uniformly-packed codes; perfect codes in the Hamming space; perfect codes in distance-regular graphs; the classification of optimal codes of a given length; and codes which are close to optimal codes by some properties, for example, Reed-Muller codes, Preparata codes, Kerdock codes and Hadamard codes. Part of the research developed by CCSG deals with Z2Z4-linear codes. There are no symbolic software to work with these codes, so the members of CCSG have been developing this new package that supports the basic facilities for Z2Z4-additive codes. Specifically, this Magma package generalizes most of the known functions for codes over the ring Z4, which are subgroups of Zn4, to Z2Z4-additive codes, which are subgroups of Zγ2 × Zδ4, maintaining all the functionality for codes over Z4 and adding new functions which, not only generalize the previous ones, but introduce new variants when it is needed. A beta version of this new package for Z2Z4-additive codes and this manual with the description of all functions can be downloaded from the web page http://ccsg.uab.cat. For any comment or further information about this package, you can send an e-mail to [email protected]. The authors would like to thank Lorena Ronquillo, Jaume Pernas, Roger Ten-Valls, and Cristina Diéguez for their contributions developing some parts of this Magma package