Codes over a ring of order 32 with two Gray maps
Steven T. Dougherty, Joe Gildea, Adrian Korban, Adam Michael Roberts · Finite Fields and Their Applications · 2024
We describe a ring of order 32 and prove that it is a local Frobenius ring. We study codes over this ring and we give two distinct non-equivalent linear orthogonality-preserving Gray maps to the binary space. Self-dual codes are studied over this ring as well as the binary self-dual codes that are the Gray images of those codes. Specifically, we show that the image of a self-dual code over this ring is a binary self-dual code with an automorphism consisting of 2 n transpositions for the first map and n transpositions for the second map. We relate the shadows of binary codes to additive codes over the ring. As Gray images of codes over the ring, binary self-dual [ 70 , 35 , 12 ] codes with 91 distinct weight enumerators are constructed for the first time in the literature.