y(n)=x(n)*h(n) ∑x(k)h(n-k)=∑al(n-k)(k) k=-∞0 k: ∑α 1-a u(n) k=0 C x(k)=au(k) h(n-k=u(n-k) k k 01 0 ( ) ( ) ( ) ( ) ( ) ( ) ( ) 1 ( ) 1 k k k n n k k y n x n h n x k h n k u n k u k u n       =− =− + = =  = − = − − = = −    0 1 k ( ) ( ) k x k u k = ... 0 1 n k h n k u n k ( ) ( ) − = −