基2时间抽取FFT算法流图 N=2 x[]={x[0],x1]} A0]=x[0+W2x X[1=x[0]+W2x[=x101-W x[ll A[0 W
基2时间抽取FFT算法流图 N=2 x[k]={x[0], x[1]} [0] [0] [1] 0 2 X = x +W x [1] [0] [1] 1 2 X = x +W x x[0] x[1] X[0] -1 0 W2 X[1] [0] [1] 0 2 = x −W x
XIm=Film+W4, m=0, Xm+21=X1[m1-W4X2[m],m=0,1 x1[0 [0] RoI W 02点DFT[xL 「21 2 X[1 X2[ W4 x[1 X[2] 2点DFT W x[3 2 X[3]
4点基2时间抽取FFT算法流图 x[0] x[2] x[1] x[3] X1 [0] X1 [1] X2 [0] X2 [1] 2点DFT 2点DFT −1 −1 −1 −1 0 W4 1 W4 0 W2 0 W2 X [0] X [1] X [2] X [3] X[m] = X1 [m] +W4 X2 [m], m = 0,1 m X[m + 2] = X1 [m] −W4 X2 [m], m = 0,1 m
4点基2时间抽取FFT算法流图 x[0 21。W X1[1 1 x2[0 W x12] 04 elr X
4点基2时间抽取FFT算法流图 x[0] x[2] x[1] x[3] −1 −1 −1 −1 X[0] X[2] X[1] X[3] X1[0] X2[0] X1[1] X2[1] 0 W4 1 W4 0 W4 0 W4