Department of Mathematical Sciences, Yamagata University, Yamagata 990–8560, Japan. E-mail:
The automorphism group of a code is useful in the study of equivalence classes of codes. In this paper, I use some methods to construct automorphism groups of Hamming codes Ā7 and A8 respectively. Hamming codes Ā7 and A8 are self-orthogonal codes, and A8 is also self-dual. I prove that the automorphism group of Ā7 and linear transformation group GL3(2) to be isomorphism, and then I extend code Ā7 to [8, 4] code. Finally I construct the automorphism group
automorphism group, selforthogonal code, selfdual code