Page 399 - Schaum's Outline of Theory and Problems of Signals and Systems
P. 399

386                             STATE SPACE ANALYSIS                            [CHAP. 7



                 In matrix form







                 The  simulation  in  Fig.  7-9  is  known  as  the  canonical  simulation  of  the  second form,  and
                 Eq. (7.91) is known  as the canonical state representation of  the second form.


           7.11.  Consider a discrete-time  LTI system with system function

                                                H(z) =
                                                        2z2 - 3z + 1
                 Find a state representation of the system.
                     Rewriting  H( z) as




                 Comparing Eq. (7.93) with  Eq. (7.84) in  Prob. 7.9, we  see that

                                 a  =-2         =1
                                  1    2       2   2     bo = 0     b, = f     b2 = 0
                 Substituting these values into Eq. (7.85) in Prob. 7.9, we  get









           7.12.  Consider a discrete-time LTI system with system function
                                                     Z      -         Z
                                       H(z) =               -                                 (7.95)
                                               2z2  - 32 + 1   2(z - l)(z - $)
                 Find a state representation of the system such that its system matrix A is diagonal.

                     First we  expand  H(z) in  partial fractions as









                 where


                 Let

                 Then                         (1 -pkz-')Yk(z) =akX(z)

                 or                          Yk(z) =pkz-IYk(z) + akX(z)
                 from which the simulation diagram in Fig. 7-10 can be drawn. Thus, H( z) = HI( z) + H2( z ) can
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