ABSTRACT
Finite Impulse Response (FIR) filters are filters whose present output is terminated from the present and past inputs, but is independent of its previous outputs. Linear phase FIR digital filters have many advantages, such as guaranteed stability, freedom from phase distortion, and low coefficient sensitivity. Such filters are used where frequency dispersion is harmful. Several methods have been proposed in the literature for reducing the complexity of sharp filters. The chapter presents the two fundamental approaches, the use of discrete Fourier series and discrete Fourier transform. In ideal filter have an infinite number of terms of its impulse response. The two basic characteristics of a window are the width of the main lobe and the ripple ratio. The MATLAB function fir1 can be used to design low-pass, high-pass, band-pass, and band-stop linear phase FIR filters.
