gB) 1离散时间信号序列 x(n)={2(2),n≥-1 1/2 n ↓/8 n )n,n+12 (n+1)={22 x(n+1) 0, n+1<-1 1/4 ,1/8 2 + − + − + = − − = + 0, 1 1 ) , 1 1 2 1 ( 2 1 ( 1) 0, 1 ) , 1 2 1 ( 2 1 ( ) 1 n n x n n n x n n n -1 0 1 2 x(n) 1 1/2 1/4 1/8 ... -2 n 例: 1-1 离散时间信号-序列 1/2 1/4 1/8 1 x(n+1) n -2 -1 0 1