数字信号处理 iE: y(n)=IDFSIX, (k). X,(k) ∑x1(k)x4(那 k=0 N2>(m)1x()m =∑(m)∑x2(k)Wmk 0 k=0 =∑(m)元(n-m)1 2 证： y n IDFS X k X k ( ) [ ( ) ( )] =  1 1 2 0 1 ( ) ( ) N kn N k X k X k W N − − = =  1 1 1 2 0 0 1 [ ( ) ] ( ) N N mk kn N N k m x m W X k W N − − − = = =   1 1 ( ) 1 2 0 0 1 ( )[ ( ) ] N N n m k N m k x m X k W N − − − − = = =   1 1 2 0 ( ) ( ) N m x m x n m − = = −  数字信号处理