设_a是F2以上f(x)为极小多项式的n级m-序列,a为f(x)的一个根,布尔函数F(x0,x1,…xm-1)=xi1xi2…xi2+G(x0,x1…,xm-1),其中1〈m〈2^n-1,2≤k≤[n/2],deg(G(x0,x1…,xm-1)〈k。论文证明了:若a^i1, a^i2,…a^i1在F2上线性无关,且F2(a^i1,a^i2,…a^i1)=F2≠F2,则非线性过滤序列b=F(L^0_a,L^1a,…L^m-1 _a)(L^i_a=(ai,ai+1,ai+2,…),i≥0)的线性复杂度LC(_b)iakhφ(n^*)(n/n^*)^k≤LC(_b)≤i=1∑^k (i^n)-n^* |a'|n∑ (k ^n/d)。
Let _a be a binary m-sequence of degree n f(x) the minimal polynomial of _a , and α a root of f(x); Let 1〈m〈2^n -1, 2≤k≤[n/2] and F(x0,x1…,xm-1)=xi1xi2…xi2+G(x0,x1…,xm-1), Where deg (G(x0,x1…,xm-1)〈k. It proved that if a^i1, a^i1, …a^i2 are linera independent over F2 and a^i1, a^i2,…a^i1∈F2^n+, which is a subfield of F2 , then the Linear Complexity of _b=F(L^0_a, L^1 _a, …, L^m-1 _a) (where L^i _a=(ai,ai+1,ai+2,…),i≥0) satisfies φ(n^*)(n/n^*)^k≤LC(_b)≤i=1∑^k (i^n)-n^* |a'|n∑ (k ^n/d).