本文将给出多尺度分析生成元的一种完全刻画.将证明:函数φ∈L^2(R)是二进多尺度分析生成元的充要条件是(1)存在{ak)∈l^2,φ(x)=∑k∈z^αkφ(2x-k);(2)存在正数A〈B,使得A≤Φ(ω)≤B,a.e.,其中Φ(ω)=∑l∈z|φ(ω+2lπ)|^2;(3)函数F(x,y)=1/y-x ∫x^y|φ(ω)|^2dω是在原点二进远离零的.
We give a complete characterization of generators for multiresolution analysis. Precisely, we prove the following results: φ∈L^2(R) is a genarator of a dyadic multireso- lution if and only if (1) there exists {ak)∈l^2, such thatφ(x)=∑k∈z^αkφ(2x-k);; (2) there exists positive numbers A and B such thatA≤Φ(ω)≤B,a.e.., where Φ(ω)=∑l∈z|φ(ω+2lπ)|^2; (3) the function F(x,y)=1/y-x ∫x^y|φ(ω)|^2dω is dyadiely away from zero at the origin.