Example 3.6:Finite-length sequence Determine the z-transform,the ROC,pole- zero-plot,for sequence:(e.g.,N=16,0<a<1) -oa冰d a<oo Solution:z-transform Xa)之e-aey,b:+图 <0 n= 1-(az)1 zN-av 1-az-I z-a ROC:lE≠0，or,>0 ROC includes z=a,z=a is not a pole. 2626 Example 3.6: Finite-length sequence ( ) ( ) 1 1 1 0 0 N N n n n n n X z a z az − − − − = = = =  1 1 . N N N z a z z a − − = − ( ) 1 1 1 1 N az az − − − = − ◆Determine the z-transform, the ROC, pole￾zero-plot, for sequence: Solution: z-transform ROC includes z=a, z=a is not a pole. , a   1 , = z az− a   ROC z or z : 0, , 0   (e.g., N=16, 0<a<1)    , 0 1 0, a n N n x n otherwise   − =