9. FREQUENCY RESPONSE OF A DIGITAL SYSTEM

FREQUENCY RESPONSE OF A DIGITAL SYSTEM

%to plot the frequency response of a digital system

b=ones(1,5);   %FIR system1

a=[1];

d=[1,-1];  %FIR system2

f=[1];

w=0:.01:2*pi;

[h,ph]=freqz(b,a,w);

[h1,ph1]=freqz(d,f,w);

magh=abs(h);

angh=angle(h);

angh1=angle(h1);

magh1=abs(h1);

subplot(2,2,1);

plot(ph/pi,magh);

grid;

ylabel('magnitude');

xlabel('normalised frequency');

subplot(2,2,2);

plot(ph1/pi,abs(h1));

grid;

ylabel('magnitude');

xlabel('normalised frequency');

subplot(2,2,3);

plot(ph/pi,angh);

grid;

xlabel('normalised frequency');

ylabel('phase in radians');

subplot(2,2,4);

plot(ph1/pi,angle(h1));

grid;

xlabel('normalised frequency');

ylabel('phase in radians');