这样逐级分解,直到2点DFT 当N=8时,即分解到X3(k),X4(k),X5(k), x6(k),k=0,1 X)=∑x()WM4=∑x(O)W的4k=0 x3(0)=x3(OW2+W2x3(1)=x(0)+Wx(4 x)=x(0)+形2x:()=x(0)-形3(4 N/4-1 X4(k)=∑x()WM4=∑x1()WM4k=01 =0 ∫X(O)=x1(O)H2+2x(1)=x(2)+Hx(6) x()=x:(0)2+2(1)=x2)-3(6这样逐级分解,直到2点DFT 当N = 8时,即分解到X3(k),X4(k),X5(k), X6(k),k = 0, 1 0 0 0 3 3 2 2 3 0 1 0 3 3 2 2 3 (0) (0) (1) (0) (4) (1) (0) (1) (0) (4) N N X x W W x x W x X x W W x x W x / 4 1 1 3 3 / 4 3 / 4 0 0 ( ) ( ) ( ) N lk lk N N l l X k x l W x l W k 0,1 0 0 0 4 4 2 2 4 0 1 0 4 4 2 2 4 (0) (0) (1) (2) (6) (1) (0) (1) (2) (6) N N X x W W x x W x X x W W x x W x / 4 1 1 4 4 / 4 4 / 4 0 0 ( ) ( ) ( ) N lk lk N N l l X k x l W x l W k 0,1