Frequency Response of FIR Filters

Graphical Representation of the Frequency ResponseExample: First-Difference System• The frequency response isHe jˆyn xn –xn – 1– = 1 – e jˆ= 1 – cosˆ+jsinˆ>> w = -pi:pi/100:pi;>> H = freqz([1 -1],1,w); %use a custom w axis>> subplot(211)>> plot(w,abs(H))>> axis([-pi pi 0 2]); grid; ylabel('Magniude Response')>> subplot(212)>> plot(w,angle(H))>> axis([-pi pi -2 2]); grid;>> ylabel('Phase Response (rad)')>> xlabel('hat(\omega)')2Magnitude Response1.510.52 sinˆ 20−3 −2 −1 0 1 2 3=Phase Response (rad)210−1atan sinˆ--------------------- 1 – cosˆ−2−3 −2 −1 0 1 2 3hat(ω)ECE 2610 Signals and Systems 6–20