In this paper, we define near-MDR （maximum distance with respect to rank） codes over the ring Z4 and prove that a linear code C over Z4 is near-MDR if and only if the torsion codes Tor（C）is near-MDS. Finally, the ...In this paper, we define near-MDR （maximum distance with respect to rank） codes over the ring Z4 and prove that a linear code C over Z4 is near-MDR if and only if the torsion codes Tor（C）is near-MDS. Finally, the generator matrices of all near-MDR codes over Z4 are given.展开更多
考虑环R=Z2a+uZ2a上的线性码,其中u2=u。研究了环R上线性码的完全Gray权估计的M ac Williams恒等式。给出了环R上的自对偶码的生成矩阵及环Z23+u Z23上长为偶数n的自对偶码的数量公式。讨论了环R上的挠码,得到挠码的生成矩阵及挠码与剩...考虑环R=Z2a+uZ2a上的线性码,其中u2=u。研究了环R上线性码的完全Gray权估计的M ac Williams恒等式。给出了环R上的自对偶码的生成矩阵及环Z23+u Z23上长为偶数n的自对偶码的数量公式。讨论了环R上的挠码,得到挠码的生成矩阵及挠码与剩余码的关系。展开更多
基金Supported by the Natural Science Foundation of Hubei Province(B2013069)the Natural Science Foundation of Hubei Polytechnic University(12xjz14A)
文摘In this paper, we define near-MDR （maximum distance with respect to rank） codes over the ring Z4 and prove that a linear code C over Z4 is near-MDR if and only if the torsion codes Tor（C）is near-MDS. Finally, the generator matrices of all near-MDR codes over Z4 are given.
