通过定义环F2+uF2上的n级deBruijn-Good图到n-1级de BruijnGood图的满同态映射D,证明了一个由环F2+uF2上n-1级de Bruijn序列的反馈函数产生咒级de Bruijn序列的反馈函数的升级算法定理;进而利用D同态的计算公式给出由m级de Bruijn序列的反馈函数产生以级(m〈n)de Bruijn序列的一个有效升级算法.
A sur-homomorphism D from n-stage de Bruijn-Good graph to (n-1)-stage de Bruijn-Good graph over ring F2+uF2 was defined. It was proved an algorithm for generating n-stage de Bruijn sequences from a given feedback function of (n-1)-stage de Bruijn sequences. Furthermore, an efficient algorithm for generating n-stage de Bruijn sequences from a given feedback function of lower m-stage de Bruijn sequences by raising stage was given.