文摘
The even-weight subcode of a binary Zetterberg code is a cyclic code with generator polynomial \(g(x)=(x+1)p(x)\), where p(x) is the minimum polynomial over GF(2) of an element of order \(2^m+1\) in \(GF(2^{2m})\) and m is even. This even binary code has parameters \([2^m+1,2^m-2m, 6]\). The quaternary code obtained by lifting the code to the alphabet \({\mathbb {Z}}_4=\{0,1,2,3\}\) is shown to have parameters \([2^m+1,2^m-2m, d_L ]\), where \(d_L \ge 8\) denotes the minimum Lee distance. The image of the Gray map of the lifted code is a binary code with parameters \((2^{m+1}+2,2^k,d_H)\), where \(d_H \ge 8\) denotes the minimum Hamming weight and \(k=2^{m+1}-4m\). For \(m=6\) these parameters equal the parameters of the best known binary linear code for this length and dimension. Furthermore, a simple algebraic decoding algorithm is presented for these \({\mathbb {Z}}_4\)-codes for all even m. This appears to be the first infinite family of \({\mathbb {Z}}_4\)-codes of length \(n=2^m+1\) with \(d_L \ge 8\) having an algebraic decoding algorithm.KeywordsZetterberg codeCyclic codesCodes over \({\mathbb {Z}}_4\)