Digital Signal Processing with Examples in MATLAB, 2nd Edition

5

FIR Filter Design

5.1    Introduction

In Chapter 4, we saw that the transfer function of a linear nonrecursive or finite impulse response (FIR) filter is the transform of the filter’s impulse response vector, the latter being equal to the filter’s weight vector. In this chapter, we discuss the simplest FIR design techniques, which are based simply on starting with a desired transfer function in the form of a discrete Fourier transform (DFT) and then obtaining the filter weights via the inverse DFT. Because many different applications take the form of one of the four filters in Figure 4.24—lowpass, highpass, bandpass, and bandstop—we focus in this chapter on these four basic types of filters.

Compared with IIR filters, FIR filters ...