Digital Signal Processing
Lab Experiment-9
Name: A.S.U. Nandan
Reg. No.: 19BEC1382
AIM :
Design for required filters with suitable frequency bands for:
i.
ii.
High-pass – Band-pass Butterworth filter
Low-pass – Band-stop Chebyshev filter
TASK – 1
HIGH PASS – BAND PASS BUTTERWORTH FILTER
CODE:
clc
clear all
close all
fs = 800;
fp = 120;
fst = 70;
[n, wn] = buttord((fp/fs), (fst/fs), 3, 20);
[b, a] = butter(n, wn, 'high');
[h, w] = freqz(b, a, 512, 800);
freqz(b, a, 512)
H = abs(h);
subplot(3,1,1);
plot(w, H);
t = 0:1/fs:0.2;
y1 = sin(2*pi*80*t);
y2 = sin(2*pi*160*t);
x = y1 + y2;
subplot(3,1,2);
plot(x);
y = filter(b, a, x);
subplot(3,1,3);
plot(y);
OUTPUT :
TASK 2 – LOWPASS – BANDSTOP CHEBYSHEV FILTER:
CODE:
clc
clear all close
all fs = 800;
fp = 200;
fst = 250;
[n,wn]=cheb
1ord((fp/fs),(
fst/fs),3,40);
[b,a]=cheby1
(n,1,wn);
[h,w]=freqz(b,a,512,800);
freqz(b,a,512)
H = abs(h); figure(1) plot(w,H);
t=0:1/fs:0.2;
y1 = (sin(2*pi*80*t)/fs); y2 =
(sin(2*pi*160*t)/fs); x = y1 + y2;
figure(2)
plot(x);
y = filter(b,a,x); figure(3)
plot(y);
OUTPUT :
OUTPUT :
RESULT:
Thus, we have done the IIR filter analysis like Butterworth & Chebyshev filtrations for our input
signals.