Introduction to Digital Signal Processing

5

The design of FIR filters

5.1 CHAPTER PREVIEW

This, the final chapter, begins by making a case for the use of FIR filters rather than IIR filters under certain conditions. We will then look at two standard methods used to design FIR filters – the ‘Fourier’ or ‘windowing’ method and the ‘frequency sampling’ method. These two design techniques rely heavily on various forms of the Fourier transform and the inverse Fourier transform, and so these topics will also be covered, including the ‘fast Fourier transform’ and its inverse.

5.2 INTRODUCTION

So far we have looked at various ways of designing IIR filters. Compared to FIR filters, IIR filters have the advantage that they need significantly fewer coefficients to produce a roughly equivalent ...