2)x(m)=a"R(m) 解:X(k)=∑x(n)R、(k) a e RN(k) k ae N R(k RN(k) ae1 2 0 ( ) N j nk n N N n a e R k (2) ( ) ( ) n N x n a R n 1 0 ( ) ( ) ( ) N nk N N n X k x n W R k 解: 2 1 ( ) 1 N N j k N a R k ae 1 2 0 ( ) n N j k N N n ae R k