摘要
利用有限环Z_4+v Z_4(其中v_2=1)上自对偶码,给出了一种构造Z_4上自对偶码的方法.引入了(Z_4+v Z_4)n到Z_2n_4的保距Gray映射,给出了Z_4+v Z_4上自对偶码的性质,证明了Z_4+v Z_4上长为n的自对偶码的Gray像是Z_4上长为_2n的自对偶码,由此构造了Z_4上一些极优的类型I与类型Ⅱ自对偶码.
A M ethod for Construction self-dual codes over Z_4 is proposed by using self-dual codes over the ring Z_4+v Z_4,where v_2= 1. A Gray map from( Z_4+ v Z_4)nto Z_2n_4 is introduced,and some properties about self-dual codes over Z_4+v Z_4 are given. It show ns that the Gray image of a self-dual code over Z_4+ v Z_4 of length n is a self-dual code over Z_4 of length _2n. Further,some extremal Type I and Type Ⅱ codes over Z_4 are constructed.
引文
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