dsp file main_2

7/31/2019 Dsp File Main_2

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Each student must have their own laboratory notebook. All pre-lab exercises and laboratory

reports are to be entered into your notebook.

Your notebook must be clearly labelled on the cover with the following information:

Digital Signal Processing


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There are 2 hours allocated to a laboratory session in Digital Signal Processing. It is a

necessary part of the course at which attendance is compulsory.

Here are some guidelines to help you perform the experiments and to submit the reports:

1. Read all instructions carefully and carry them all out.2. Ask a demonstrator if you are unsure of anything.3. Record actual results (comment on them if they are unexpected!)4. Write up full and suitable conclusions for each experiment.5. If you have any doubt about the safety of any procedure, contact the demonstrator

beforehand.

6. about what you are doing!


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1. To write a program to represent basic signal (unit step, unit impulse, ramp,exponential, Sine sequence, Cosine sequence).

2. To perform the discrete convolution of sequences.3. To write a program for discrete correlation.

(a)Program for computing cross correlation of the sequences

(b) Program for computing auto correlation.

4. To design(a) Program for low pass IIR butterworth filter(b) Program for high pass IIR butterworth filter

5. To Design a digital filter using rectangular window method.(a)Program for low pass filter(b)Program for high pass filter(c) Program for band pass filter(d)Program for band stop filter

6. To design(a) Program for low pass filter(b) Program for high pass filter(c) Program for band pass filter(d) Program for band stop filter


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To write a program to represent basic signal (unit step, unit impulse, ramp,

exponential, Sine sequence, Cosine sequence)

MATLAB SOFTWARE, PC

clc;

clearall;

close all;

n=input('enter the N value');

t=0:1:n-1;

y1=ones(1,n);subplot(2,2,1);

stem(t,y1); ylabel('Amplitude -->');

xlabel('(a) n -->');

title('unit step signal');

t=-2:1:2;

y=[zeros(1,2),ones(1,1),zeros(1,2)];

subplot(2,2,2);

stem(t,y);

ylabel('Amplitude -->');

xlabel('(b)n -->');

title('unit impulse signal');

n1=input('eneter the length of ramp sequence');

t=0:n1;

subplot(2,2,3);

stem(t,t);ylabel('Amplitude -->');


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xlabel('(c)n -->');

title('Unit ramp sequence');

n2=input('enter the length exponential sequence');

t=0:n2;

a=input('enter the value of a');

y2=exp(a*t);

subplot(2,2,4);

stem(t,y2);


xlabel('(d)n -->');

title('exponential sequence');

enter the N value7

eneter the length of ramp sequence7enter the length exponential sequence7

enter the value of a1


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Program to represent basic signal (unit step, unit impulse, ramp, exponential, Sine

sequence, Cosine sequence).


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n=0:.01:pi;

y=sin(2*pi*n);

subplot(2,2,1);

stem(n,y);

xlabel('(a)n');


title('Sine Sequence');

n=0:.01:pi;

y1=cos(2*pi*n);

subplot(2,2,2);

stem(n,y1);

xlabel('(b)n');

ylabel('Amplitude -->');title('cosine sequence');


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Program to represent basic signal (Sine sequence, Cosine sequence)


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To perform the discrete convolution of sequences.

MATLAB SOFTWARE, PC

clc;

clear all;

close all;

x=input('enter the first sequence');

h=input('enter the second sequence');

y=conv(x,h)

figure;

subplot(3,1,1);

stem(x);

ylabel('amplitude');

xlabel ('(a)n');

subplot(3,1,2);

stem(h);


xlabel ('(b)n');

subplot(3,1,3);

stem(y);


xlabel ('(c)n');

disp (The resultant signal is ); y

title('convolution');


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enter the first sequence [1 2]

enter the second sequence [1 2 4]

The resultant signal is

y = 1 4 8 8


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Program for convolution of two discrete sequences


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To write a program for discrete correlation.

MATLAB SOFTWARE, PC

clc; clear all; close all;

x=input('enter the first sequence');

h=input('enter the second sequence');

y=xcorr(x,h);

figure;

subplot(3,1,1);

stem(x);



title('First Input sequence');

subplot(3,1,2);

stem(h);

xlabel('(b) n -->'); ylabel('Amplitude -->');title('Second Input sequence');

subplot(3,1,3);

stem(y);

xlabel('(c) n -->');


title('Output sequence');

disp ('The resultant signal is'); y


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enter the first sequence[1 2 3 4]

enter the second sequence[4 3 2 1]


y =

Columns 1 through 3

1.0000 4.0000 10.0000

Columns 4 through 6

20.0000 25.0000 24.0000

Column 7

16.0000


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( A)Program for computing cross correlation of the sequences


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(

clc; clear all; close all;

x=input('enter the sequence');

y=xcorr(x,x);

figure;

subplot(2,1,1);

stem(x);



subplot(2,1,2);

stem(y);

xlabel('(b) n -->');


disp ('The resultant signal is'); y

enter the sequence[1 2 3 4]


y =

Columns 1 through 3

4.0000 11.0000 20.0000

Columns 4 through 6

30.0000 20.0000 11.0000

Column 7

4.0000


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(B)Program for computing auto correlation function


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To design IIR butterworth filter.

MATLAB SOFTWARE, PC

clc;

close all;

clear all;

rs=input('enter the stop band ripple ');

rp=input('enter the pass band ripple ');

ws=input('enter the stop band frequency ');

wp=input('enter the pass band freequency ');

fs=input('enter the sampling frequency ');

w1=2*wp/fs;

w2=2*ws/fs;

%to find the cutoff frequency and order of the filter

[n,wn]=buttord(w1,w2,rp,rs);

%system function of the filter

[b,a]=butter(n,wn)

w=0:0.01:pi;

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

m=abs(h);

an=angle(h);


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subplot(2,1,1);

plot(om/pi,20*log10(m));grid

ylabel('gain in db ');

xlabel('(a) normalised frequency ');

subplot(2,1,2);

plot(om/pi,an);grid

ylabel('phase in radian');

xlabel('(b) normalised frequency ');

enter the stop band ripple 30

enter the pass band ripple 0.40

enter the stop band frequency 800

enter the pass band freequency 400

enter the sampling frequency 2000

b =0.1518 0.6073 0.9109 0.6073 0.1518

a = 1.0000 0.6418 0.6165 0.1449 0.025


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(A) Program for low pass IIR butterworth filter


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clc;

close all;

clear all;

rs=input('enter the stop band ripple ');

rp=input('enter the pass band ripple ');

ws=input('enter the stop band frequency ');

wp=input('enter the pass band freequency ');

fs=input('enter the sampling frequency ');

w1=2*wp/fs;

w2=2*ws/fs;

%to find the cutoff frequency and order of the filter

[n,wn]=buttord(w1,w2,rp,rs);

%system function of the filter

[b,a]=butter(n,wn,'high')

w=0:0.01:pi;

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

m=abs(h);

an=angle(h);

subplot(2,1,1);

plot(om/pi,20*log10(m));grid

ylabel('gain in db ');

xlabel('(a) normalised frequency ');

subplot(2,1,2);

plot(om/pi,an);grid

ylabel('phase in radian');

xlabel('(b) normalised frequency ');


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enter the stop band ripple 30

enter the pass band ripple .4

enter the stop band frequency 800

enter the pass band freequency 400

enter the sampling frequency 2000

b =0.0535 -0.2139 0.3209 -0.2139 0.0535

a =1.0000 0.6418 0.6165 0.1449 0.0259


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(B) Program for high pass IIR butterworth filter


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To Design a digital filter using rectangular window method.

MATLAB SOFTWARE, PC

clc;

close all;

clear all;

wc=0.5*pi;%cut off frequency

N=25;

alpha=(N-1)/2;eps=0.001;%to avoid indeterminate form

n=0:1:N-1;

hd=sin(wc*(n-alpha+eps))./(pi*(n-alpha+eps));

wr=boxcar(N);%rectangular window sequence

hn=hd.*wr';%filter coefficients

w=0:0.01:pi;

h=freqz(hn,1,w);

%plot magnitude response

m=abs(h);

subplot(2,1,1);

plot(w/pi,m);grid

xlabel('normalized frequency');

ylabel('magnitude');

title('magnitude response of low pass filter using rectangular window');

an=angle(h);


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subplot(2,1,2);

plot(w/pi,an);grid


ylabel('phase shift');

title('phase response of low pass filter using rectangular window');


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(A) Program for low pass filter


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clc;

close all;

clear all;

wc=0.5*pi;%cut off frequency

N=25;

alpha=(N-1)/2;

eps=0.001;%to avoid indeterminate form

n=0:1:N-1;

hd=sin(pi*(n-alpha+eps))-sin(wc*(n-alpha+eps))./(pi*(n-alpha+eps));



w=0:0.01:pi;

h=freqz(hn,1,w);


m=abs(h);

subplot(2,1,1);

plot(w/pi,m);grid



title('magnitude response of high pass filter using rectangular window');

%plot phase response

an=angle(h);

subplot(2,1,2);

plot(w/pi,an);grid



title('phase response of high pass filter using rectangular window');


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(B) program for high pass filter


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clc;

close all;

clear all;

wc1=0.25*pi;

wc2=0.75*pi;

N=25;

alpha=(N-1)/2;


n=0:1:N-1;

hd=(sin(wc2*(n-alpha+eps))-sin(wc1*(n-alpha+eps)))./(pi*(n-alpha+eps));



w=0:0.01:pi;

h=freqz(hn,1,w);


m=abs(h);

subplot(2,1,1);

plot(w/pi,m);grid



title('magnitude response of band pass filter using rectangular window');


an=angle(h);

subplot(2,1,2);

plot(w/pi,an);grid



title('phase response of band pass filter using rectangular window');


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(C) Program for band pass filter


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clc;

close all;

clear all;

wc1=0.25*pi;

wc2=0.75*pi;

N=25;

alpha=(N-1)/2;


n=0:1:N-1;

hd=(sin(pi*(n-alpha+eps))+sin(wc1*(n-alpha+eps))-sin(wc2*(n-alpha+eps)))./(pi*(n-

alpha+eps));



w=0:0.01:pi;

h=freqz(hn,1,w);


m=abs(h);

subplot(2,1,1);

plot(w/pi,m);grid


ylabel('magnitude');title('magnitude response of band stop filter using rectangular window');


an=angle(h);

subplot(2,1,2);

plot(w/pi,an);grid




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title('phase response of band stop filter using rectangular window');


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(D) Program for band stop filter


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To design the program for analog butterworth filter.

MATLAB SOFTWARE, PC

clc;

clear all;

close all;

rs=input('enter the stopband ripple=');

rp=input('enter the passband ripple=');

ws=input('enter the stopband frequency=');

wp=input('enter the passband frequency=');

fs=input('enter the sampling frequency=');

w1=2*wp/fs;

w2=2*ws/fs;

%find the order and cut off frequency

[n,wn]=buttord(w1,w2,rs,rp,'s');

%calculating system function

[b,a]=butter(n,wn,'s');

%plot frequency response

w=0:0.01:pi;

[h,w]=freqs(b,a,w);

m=20*log10(abs(h));

subplot(2,1,1);plot(w/pi,m);grid


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ylabel('Gain in dB--');

xlabel('Normalised Frequency--');

title('Magnitude Response of low pass filter');

an=angle(h);

subplot(2,1,2);

plot(w/pi,an); grid

ylabel('Phase in radians--');


title('Phase Response of low pass filter');

enter the stopband ripple=.25

enter the passband ripple=60

enter the stopband frequency=3000

enter the passband frequency=2000

enter the sampling frequency=9000

n =21 wn =0.4798


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(A)Program for low pass filter


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clc;

clear all;

close all;






w1=2*wp/fs;

w2=2*ws/fs;


[n,wn]=buttord(w1,w2,rs,rp,'s');


[b,a]=butter(n,wn,'high','s');


w=0:0.01:pi;

[h,w]=freqs(b,a,w);

m=20*log10(abs(h));

subplot(2,1,1);plot(w/pi,m);grid



title('Magnitude Response of high pass filter');

an=angle(h);

subplot(2,1,2);

plot(w/pi,an); grid



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title('Phase Response of high pass filter');

enter the stopband ripple=.25





n = 21

wn =0.4798


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(B) Program for high pass filter


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clc;

clear all;

close all;






w1=2*wp/fs;

w2=2*ws/fs;


[n]=buttord(w1,w2,rs,rp,'s')

wn=[w1,w2]


[b,a]=butter(n,wn,'bandpass','s');


w=0:0.01:pi;

[h,w]=freqs(b,a,w);

m=20*log10(abs(h));subplot(2,1,1);

plot(w/pi,m);grid



title('Magnitude Response of band pass filter');

an=angle(h);

subplot(2,1,2);

plot(w/pi,an); grid


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title('Phase Response of band pass filter');

-

enter the stopband ripple=50





n = 9

wn = 1.7778 1.5556


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(C) Program for band pass filter


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clc;

clear all;

close all;






w1=2*wp/fs;

w2=2*ws/fs;


[n]=buttord(w1,w2,rs,rp,'s')

wn=[w1,w2]


[b,a]=butter(n,wn,'stop','s');


w=0:0.01:pi;

[h,w]=freqs(b,a,w);

m=20*log10(abs(h));subplot(2,1,1);

plot(w/pi,m);grid

ylabel('Gain in dB--')

xlabel('Normalised Frequency--')

title('Magnitude Response of band stop filter');

an=angle(h);

subplot(2,1,2);

plot(w/pi,an); grid


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ylabel('Phase in radians--')

xlabel('Normalised Frequency--')

title('Phase Response of band stop filter');

enter the stopband ripple=50





n = 9

wn = 1.7778 1.5556


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(D) Program for band stop filter

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