DIGITALSIGNALPROCESSING
                   LECTURE11
                   Fall 2010
                   2K8-5th Semester
                   Tahir MuhammadTahir Muhammad
                   tmuhammad_07@yahoo.com
               Content and Figures are from Discrete-Time Signal Processing, 2e by Oppenheim, 
                                  Shafer, and Buck, ©1999-2000 Prentice Hall Inc.
           FILTER DESIGN TECHNIQUES
           | FilFilter:
               y Any discrete-time system that modifies certain frequencies
           | Freqequeencycy-seselecective ve efilters pass os pass only cey certaain  freqequeenccy y 
              components and totally reject all others
           | Filter Design Steps:
               y SiSpecifificatition
                   | Problem or application specific
               y Approximation of specification with a discrete-time system
                   | O fOur focus  is  to  go f from  spec  to  discrete-time  system
               y Implementation
                   | Realization of discrete-time systems depends on target technology
           | Desired filter is generally implemented with digital 
              computation
               y It is used to filter a samppgled and digitized continuous-time siggnal
                                        Chapter 7: Filter Design Techniques                       1
               FILTER DESIGN TECHNIQUES
                     | W hWe have  allreaddy  sttudidided th the  use  of dif discrette-titime t systems  tto  
                         implement a continuous-time system
                           y If our specifications are given in continuous time we can use:
                                                                                                                               jjωω
                                                                                                                       HHH   e       =Hjjω//TT
                                                                            [ ]                                            ((     ))         ((          ))
                                                     [ ]                   y n
                                                   x n             jω                                                                      c
                   xc(t)               C/D                  H(e )                    D/C               yr(t)                        ωπ<
                           y It can be noted that the specifications for filters are typically 
                               given in frequency domain 
                                                              Chapter 7: Filter Design Techniques                                                        2