山东大学2011-2012学年2学期数字信号处理（双语）课程试卷(B)答案与评分细则 8.(10 pts)Solution: 6.(15pts)Solution: x0] 0+oXI0例 (a)The difference equation relating x[n]and y[n]:(7pts) x nm+1.9n-月-1.08fn-2]+0.18fn-3]=7.96-10.13[n-刂+2.87xn-2] +0X2] (b)Rearrange the system function: W He=2870.18-X235-e 6] 2.871.18-2.35-e4 x3]9 1-0-0.320-0.621-*1-0.32-*1-0.6e✉ x[4] 0→一0XT10 The signal flow graph of cascade structure of the system with Ist-order sections is x[5] x(n). 2.87 1.18 2.35 yn) x[6] →-0X3 x(7 (8 pts) 7.(15 pts)Solution: 因-2- …7p otherwise 四[网=x0冈=9-h5sn≤9 [n+l,0≤n≤4 器 x[0]=l,x[=2,x[2]=3,x[B]=4,x[4=5,x[5=4, x[6]=3,[]=2,x[8=l[9]=0 ,8 暴 第2项共2页2011-2012 2 数字信号处理（双语） （B）答案与评分细则 2 2 6．(15 pts) Solution: (a) The difference equation relating x[n] and y[n]： （7pts） y n y n y n y n x n x n x n [ ] 1.9 [ 1] 1.08 [ 2] 0.18 [ 3] 7.96 [ ] 10.13 [ 1] 2.87 + − − − + − = − − + − [ 2] (b) Rearrange the system function: 1 1 1 1 1 2.87(1.18 )(2.35 ) ( ) (1 )(1 0.3 )(1 0.6 ) z z H z z z z − − − − − − − = − − − 1 1 1 1 1 2.87 1.18 2.35 1 1 0.3 1 0.6 z z z z z − − − − − − − =   − − − The signal flow graph of cascade structure of the system with 1st-order sections is （8 pts） 7．(15 pts) Solution: (a) . (b) 8．(10 pts) Solution: x n( ) y n( ) −1 2.87 1.18 1 z − 1 1 z − 0.3 −1 1 z − 0.6 2.35   4 1 5 0 5, 0 0, =  = = =    kn n k X k W otherwise x n x n x n 3 1 2   =  10                       3 3 3 3 3 3 3 3 3 3 0 1, 1 2, 2 3, 3 4, 4 5, 5 4, 6 3, 7 2, 8 1, 9 0 = = = = = = = = = = x x x x x x x x x x 1, 0 4 9 , 5 9  +   =   −   n n n n 7 pts 8 pts