9.2 decimation-in-time FFT Algorithms G0 x00→ X[O] WS ◆Repeat same process,Divide。 G -Point N PX[1] WN N/2-point DFTs into G[2] x[4。→ DFT X[2] w ◆TwoN/4-point DFTs G[3] x[6。→ X[3] w ◆Combine outputs x10→ X[4] H[o] w x3o→ N X5] x[2r+1] 2 -point H DFT N=8 x[5)o→ X6 x[n]=x[2r] H(2] x7]0→ X7列 H(3] x[0]o￥ 2*2列 N G[0] 4 -point w92→ WN2-WS DFT W2=W吹 「x[2] 2*2+1 4 -point w Gel.WR=WN WNR ⑥。→ DFT WNR=WN 1019 9.2 decimation-in-time FFT Algorithms ◆Repeat same process , Divide N/2-point DFTs into ◆Two N/4-point DFTs ◆Combine outputs N=8 0 0 W W N N /2= 1 2 W W N N /2= 2 4 W W N N /2= 3 6 W W N N /2= x[n]=x[2r] x[2*2s] x[2*(2s+1)] x[2r+1]