R 986 INSTITUTE OF ARTIFICIAL INTELLIGENCE AND ROBOTICS. XJTU 同样,利用对称性 若y( n)=X,n 则(k)=DFS(n)=∑(m)WXW k 1人文(1)(k-1 N ∑()X(k-D 数字信号处理简明教程Institute of Artificial Intelligence and Robotics, XJTU 1986 数字信号处理简明教程 同样，利用对称性 1 1 2 0 1 ( ) ( ) N l X l X k l N − = = −  1 2 1 0 1 ( ) ( ) N l X l X k l N − = = −  1 2 若 y n x n x n ( ) ( ) ( ) = 1 0 ( ) [ ( )] ( ) N nk N n Y k DFS y n y n W − = 则 = = 