SCIENSITY: mat lab programs and output

Friday 6 January 2012

mat lab programs and output

AM WAVE GENERATION

aim

Write a MATLAB program to display AM wave.

PROGRAM

clc;

t=0:0.0001:0.01;

m=input('Enter the modulation index:');

fm=input('Enter the freq: of modulated wave:');

fc=input('Enter the freq: of carrier wave:');

x=sin(2*pi*fm*t);

y=sin(2*pi*fc*t);

e=(1+(m.*x).*y);

plot(e);

title('AM Wave');

xlabel('Time Index');

ylabel('Amplitude');

result

Enter the modulation index:.5

Enter the freq: of modulated wave:100

Enter the freq: of carrier wave:2000

WAVEFORM

AMPLITUDE MODULATION

AIM

Write aMATLAB program for Amplitude Modulation

PROGRAM

clc;

clear all;

A=0.7; %amplitude

f=250;

fc=4e3;

fs=10*fc;

Ts=1/fs;

T=1/f;

Nc=3*T;

t=0:Ts:Nc;

x=A*sin(2*pi*f*t);

c=A*cos(2*pi*fc*t);

y=modulate(x,fc,fs,'amdsb-tc');

z=demod(y,fc,fs,'amdsb-tc');

figure(1);

subplot(4,1,1);

plot(t,x);

axis([0 Nc -A A]);

title('Message Signal');

title('Amplitude Modulation-DSB TC');

subplot(4,1,2);

plot(t,c);

axis([0 Nc -A A]);

title('Carrier Signal');

subplot(4,1,3);

plot(t,y);

axis([0 Nc -A A]);

title('Modulated Signal');

subplot(4,1,4);

plot(t,z);

xlabel('Time');

title('Demodulated Signal');

grid;

disp('Amplitude Modulation');

disp('---------------------');

disp('Message Signal');

disp('***************');

disp(['Amplitude= ' num2str(A) 'volts']);

disp(['Time period= ' num2str(T*1000) 'msec']);

disp(['Frequency= ' num2str(f) 'Hz']);

disp('**************');

RESULT

Amplitude Modulation

---------------------

Message Signal

***************

Amplitude= 0.7volts

Time period= 4msec

Frequency= 250Hz

**************

WAVEFORM

CIRCULAR CONVOLUTION OF SEQUENCE

AIM

Write a MATLAB program for circular convolution.

PROGRAM

clc;

clear all;

close all;

disp('Circular Convolution Program');

x=input('Enter i/p sequence x(n):');

m=length(x);

h=input('Enter i/p sequence h(n):');

n=length(h);

subplot(2,2,1), stem(x);

title('i/p sequencce x(n)is:');

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

ylabel('---->x(n)');grid;

subplot(2,2,2), stem(h);

title('i/p sequencce h(n)is:');

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

ylabel('---->h(n)');grid;

disp('Circular convolution of x(n) & h(n) is y(n):');

if(m-n~=0)

if(m>n)

h=[h,zeros(1,m-n)];

n=m;

end

x=[x,zeros(1,n-m)];

m=n;

end

y=zeros(1,n);

y(1)=0;

a(1)=h(1);

for j=2:n

a(j)=h(n-j+2);

end

%ciruclar conv

for i=1:n

y(1)=y(1)+x(i)*a(i);

end

for k=2:n

y(k)=0;

% circular shift

for j=2:n

x2(j)=a(j-1);

end

x2(1)=a(n);

for i=1:n

if(i<n+1)a(i)=x2(i);

y(k)=y(k)+x(i)*a(i);

end

subplot(2,2,[3,4]),stem(y);

title('Convolution of x(n) & h(n) is:');

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

ylabel('---->y(n)');grid;

RESULT

Enter i/p sequence x(n):[1 2 3]

Enter i/p sequence h(n):[2 4 6]

Circular convolution of x(n) & h(n) is y(n):

y = 26 26 20

WAVEFORM

CIRCULAR CONVOLUTION

AIM

Write a MATLAB program for circular convolution

%solution for section(a)

clc;

close all;

clear all;

f1=1/128;

f2=5/128;

n=0:255;

fc=50/128;

x=cos(2*pi*f1*n)+cos(2*pi*f2*n);

xc=cos(2*pi*fc*n);

xamp=x.*xc;

subplot(2,2,1);

plot(n,x);

title('x(n)');

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

ylabel('amplitude');

subplot(2,2,2);

plot(n,xc);

title('xc(n)');

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

ylabel('amplitude');

subplot(2,2,3);

plot(n,xamp);

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

ylabel('amplitude');

%solution for section(b)

n=0:127;

figure;

n1=128;

f1=1/128;

f2=5/128;

fc=50/128;

x=cos(2*pi*f1*n)+cos(2*pi*f2*n);

xc=cos(2*pi*fc*n);

xa=cos(2*pi*fc*n);

xamp=x.*xa;

xam=fft(xamp,n1);

stem(n,xam);

title('xamp(n)');

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

ylabel('amplitude');

%solution for section(c)

n=0:99;

figure;

n2=0:n1-1;

f1=1/128;

f2=5/128;

fc=50/128;

x=cos(2*pi*f1*n)+cos(2*pi*f2*n);

xc=cos(2*pi*fc*n);

xa=cos(2*pi*fc*n);

xamp=x.*xa;

for i=1:100,

xamp1(i)=xamp(i);

end;

xam=fft(xamp1,n1);

stem(n2,xam);

title('xamp(n)');

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

ylabel('amplitude');

RESULT

WAVEFORM 1

WAVEFORM 2

WAVEFORM 3

CONVOLUTION OF TWO SEQUENCES

AIM

Write a MATLAB program for convolution of two sequences

PROGRAM

x=[1,0,1,2,-1,3,2];

N1=length(x);

n=0:1:N1-1;

subplot(2,2,1);

stem(n,x);

xlabel('n');

ylabel('x(n)');

h=[1 ,1, 2, 2,1,1];

N2=length(h);

n1=0:1:N2-1;

subplot(2,2,2);

stem(n1,h);

xlabel('n');

ylabel('h(n)');

y=conv(x,h);

n2=0:1:N1+N2-2;

subplot(2,2,3);

stem(n2,y);

xlabel('n');

ylabel('y(n);

OUTPUT WAVEFORM

SINEWAVE GENERATION

AIM

Write a MATLAB program to display sinewaves of different frequencies

PROGRAM

clc;

%first plot

f=input('Enter frequency 1=');

t=0:0.001:1;

x=sin(2*pi*f*t);

subplot(221);

plot(x);

title('Sinewave1');

xlabel('Time Index');

ylabel('Amplitude');

%second plot

f=input('Enter frequency 2=');

t=0:0.001:1;

x=sin(2*pi*f*t);

subplot(222);

plot(x);

title('Sinewave2');

xlabel('Time Index');

ylabel('Amplitude');

%third plot

f=input('Enter frequency 3=');

t=0:0.001:1;

x=sin(2*pi*f*t);

subplot(223);

plot(x);

title('Sinewave3');

xlabel('Time Index');

ylabel('Amplitude');

%fourth plot

f=input('Enter freequency 4=');

t=0:0.001:1;

x=sin(2*pi*f*t);

subplot(224);

plot(x);

title('Sinewave4');

xlabel('Time Index');

ylabel('Amplitude');

RESULT

Enter frequency 1=2

Enter frequency 2=5

Enter frequency 3=10

Enter frequency 4=20

WAVEFORM

FFT SEQUENCE

AIM

Write a MATLAB program to display FFT sequence

PROGRAM

clc;

close all;

clear all;

x=input('Enter the sequence:');

n=input('Enter the length of FFT:');

k=1:n;

X(k)=fft(x,n);

stem(X(k),k);

ylabel('Imaginary axis---->');

xlabel('Real axis------>');

RESULT

Enter the sequence:[2 4 7]

Enter the length of FFT:4

WAVEFORM

FAST FOURIER TRANSFORM

AIM

Write a MATLAB program for FFT

PROGRAM

clc;

clear all;

close all;

tic;

x=input('Enter the sequence:');

n=input('Enter the length of fft:');

%compute fft

disp('Fourier transformed signal');

X=fft(x,n)

subplot(1,2,1);

stem(x);

title('i/p signal');

xlabel('n --->');

ylabel('x(n) -->');grid;

subplot(1,2,2);stem(X);

title('FFT of i/p x(n) is:');

xlabel('Real axis --->');

ylabel('Imaginary axis -->');

grid;

RESULT

Enter the sequence:[1 3 5]

Enter the length of fft:4

Fourier transformed signal

X = 9.0000 -4.0000 - 3.0000i 3.0000 -4.0000 + 3.0000i

WAVEFORM

FIR LOWPASS FILTER

AIM

Write a MATLAB program to design FIR lowpass filter using hamming and blackmann windows

PROGRAM

clear all;

wc=.5*pi;%cutoff frequency

N=25;

b=fir1(N,wc/pi,hamming(N+1));

w=0:.01:pi;

h=freqz(b,1,w);

plot(w/pi,abs(h));

hold on

b=fir1(N,wc/pi,blackman(N+1))

w=0:.01:pi;

h=freqz(b,1,w);

plot(w/pi,abs(h),'-.');

ylabel('Magnitude');

xlabel('Normalised frequency');

hold off

RESULT

b =

Columns 1 through 10

-0.0000 -0.0001 -0.0005 0.0014 0.0031 -0.0060 -0.0107 0.0180 0.0291 -0.0465

Columns 11 through 20

-0.0764 0.1415 0.4472 0.4472 0.1415 -0.0764 -0.0465 0.0291 0.0180 -0.0107

Columns 21 through 26

-0.0060 0.0031 0.0014 -0.0005 -0.0001 -0.000

WAVEFORM

FREQUENCY MODULATION

AIM

Write a MATLAB program for Frequency Modulation

PROGRAM

clc;

clear all;

A=0.7; %amplitude

f=200;

fc=4e3;

fs=10*fc;

Ts=1/fs;

T=1/f;

Nc=3*T;

t=0:Ts:Nc;

x=A*sin(2*pi*f*t);

c=A*cos(2*pi*fc*t);

kf=0.6;

y=modulate(x,fc,fs,'fm',kf);

z=demod(y,fc,fs,'fm',kf);

figure(1);

subplot(4,1,1);

plot(t,x);

title('Message Signal');

grid;

subplot(4,1,2);

plot(t,c);

title('Carrier Signal');

grid;

subplot(4,1,3);

plot(t,y);

title('Modulated Signal');

grid;

subplot(4,1,4);

plot(t,z);

xlabel('Time');

title('Demodulated Signal');

grid;

disp('Frequency Modulation');

disp('---------------------');

disp('Message Signal');

disp('***************');

disp(['Amplitude= ' num2str(A) 'volts']);

disp(['Time period= ' num2str(T*1000) 'msec']);

disp('--------------------');

disp('Carrier Signal');

disp('***************');

disp(['Frequency= ' num2str(fc) 'Hz']);

disp('**************');

RESULT

Frequency Modulation

---------------------

Message Signal

***************

Amplitude= 0.7volts

Time period= 5msec

--------------------

Carrier Signal

***************

Frequency= 4000Hz

**************

WAVEFORM

IIR FILTER RESPONSES

AIM

Write a MATLAB programs of IIR filter responses for LPF & HPF

PROGRAM

clc;

clear all;

close all;

warning off;

disp('Enter the IIR filter design specifications:');

rp=input('Enter the passband ripple:');

rs=input('Enter the stopband ripple:');

wp=input('Enter the passband freq:');

ws=input('Enter the stopband freq:');

fs=input('Enter the sampling freq:');

w1=2*wp/fs;w2=2*ws/fs;

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

c=input('Enter choice of filter 1. LPF 2. HPF \n ');

if(c==1)

disp('Frequency response of IIR LPF is:');

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

end

if(c==2)

disp('Frequency response of IIR HPF is:');

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

end

w=0:.01:pi;

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

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

an=angle(h);

figure,subplot(2,1,1);plot(om/pi,m);

title('Magnitude response of IIR filter is:');

xlabel('(a) Normalized freq. -->');

ylabel('Gain in dB-->');

subplot(2,1,2);plot(om/pi,an);

title('phase response of IIR filter is:');

xlabel('(b) Normalized freq. -->');

ylabel('Phase in radians-->');

RESULT

Enter the IIR filter design specifications:

Enter the passband ripple:1

Enter the stopband ripple:2

Enter the passband freq:30

Enter the stopband freq:60

Enter the sampling freq:1

Enter choice of filter 1. LPF 2. HPF

Frequency response of IIR LPF is:

WAVEFORM

LINEAR CONVOLUTION

AIM

Write a MATLAB program for linear convolution

PROGRAM

clc;

clear all;

close all;

disp('Linear convolution program:');

x=input('Enter i/p x(n):');

m=length(x);

h=input('Enter i/p h(n):');

n=length(h);

x=[x,zeros(1,n)];

subplot(2,2,1), stem(x);

title('i/p sequence x(n)is:');

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

ylabel('---->x(n)');grid;

h=[h,zeros(1,m)];

subplot(2,2,2), stem(h);

title('i/p sequence h(n)is:');

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

ylabel('---->h(n)');grid;

disp('Convolution of x(n) & h(n) is y(n):');

y=zeros(1,m+n-1);

for i=1:m+n-1

y(i)=0;

for j=1:m+n-1

if(j<i+1)

y(i)=y(i)+x(j)*h(i-j+1);

end

subplot(2,2,[3,4]),stem(y);

title('Convolution of x(n) & h(n) is :');

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

ylabel('---->y(n)');grid;

RESULT

Linear convolution program:

Enter i/p x(n):[1 2 3]

Enter i/p h(n):[2 4 6]

Convolution of x(n) & h(n) is y(n):

y = 2 8 20 24 18

WAVEFORM

PAM MODULATION AND DEMODULATION

AIM

Write a MATLAB program for Pulse Amplitude Modulation and Demodulation

PROGRAM

clc;

clear all;

fm=5;

t=0:0.001:1;

vm=sin(2*pi*fm*t);

d=0:(1/56):2;

y=pulstran(t,d,'rectpuls',0.01);

s=y.*vm;

subplot(4,1,1);

plot(t,vm);

subplot(4,1,2);

plot(t,y);

subplot(4,1,3);

plot(t,s);

[b a]=butter(4,0.02,'low');

k=filter(b,a,s);

subplot(4,1,4);

plot(t,k);

OUTPUT WAVEFORM

PHASE MODULATION

AIM

Write a MATLAB program for Phase Modulation

PROGRAM

clear all;

A=0.5; %amplitude

f=250;

fc=4e3;

fs=10*fc;

Ts=1/fs;

T=1/f;

Nc=2*T;

t=0:Ts:Nc;

x=A*sin(2*pi*f*t);

c=A*cos(2*pi*fc*t);

kp=5;

y=modulate(x,fc,fs,'pm',kp);

z=demod(y,fc,fs,'pm',kp);

subplot(4,1,1);

plot(t,x);

title('Message Signal');

axis([0 Nc -A A]);

zoom;

grid;

subplot(4,1,2);

plot(t,c);

title('Carrier Signal');

grid;

subplot(4,1,3);

plot(t,y);

title('Modulated Signal');

grid;

subplot(4,1,4);

plot(t,z);

title('Demodulated Signal');

grid;

xlabel('Time');

disp('Phase Modulation');

disp('----------------');

disp('Message Signal');

disp('****************');

disp(['Amplitude= ' num2str(A) 'volts']);

disp(['Frequency= ' num2str(f) 'Hz']);

disp(['Time period= ' num2str(T*1000) 'msec']);

disp('Carrier signal');

disp(['Frequency= ' num2str(fc) 'Hz']);

RESULT

Phase Modulation

----------------

Message Signal

****************

Amplitude= 0.5volts

Frequency= 250Hz

Time period= 4msec

Carrier signal

****************

Frequency= 4000Hz

WAVEFORM

PPM MODULATION AND DEMODULATION

AIM

Write a MATLAB program for pulse position modulation and demodulation

PROGRAM

clear all;

clc;

am=0.4;

fm=5;

fc=10;

fs=1000;

t=0:0.01:1;

vm=0.5+am*sin(2*pi*fm*t);

x=abs(vm);

subplot(3,1,1);

plot(t,x);

[s t]=modulate(vm,fc,fs,'ppm');

subplot(3,1,2);

plot(t,s);

z=demod(s,fc,fs,'ppm');

subplot(3,1,3);

plot(z);

OUTPUT WAVEFORM

PWM MODULATION AND DEMODULATION

AIM

Write a MATLAB program for pulsewidth modulation and demodulation

PROGRAM

clear all;

clc;

am=0.4;

fm=5;

fc=5;

fs=1000;

t=0:0.01:1;

vm=0.5+am*sin(2*pi*fm*t);

x=abs(vm);

subplot(3,1,1);

plot(t,x);

[s t]=modulate(vm,fc,fs,'pwm','centered');

subplot(3,1,2);

plot(t,s);

z=demod(s,fc,fs,'pwm','centered');

subplot(3,1,3);

plot(z);

OUTPUT WAVEFORM

SUM OF SINE SIGNALS

AIM

Write a MATLAB program to display the sum of sinusoidal signals

PROGRAM

clc;

clear all;

close all;

tic;

%giving linear spaces

t=0:.01:pi;

% t=linspace(0,pi,20);

%generation of sine signals

y1=sin(t);

y2=sin(3*t)/3;

y3=sin(5*t)/5;

y4=sin(7*t)/7;

y5=sin(9*t)/9;

y = sin(t) + sin(3*t)/3 + sin(5*t)/5 + sin(7*t)/7 + sin(9*t)/9;

plot(t,y,t,y1,t,y2,t,y3,t,y4,t,y5);

legend('y','y1','y2','y3','y4','y5');

title('Generation of sum of sinusoidal signals');grid;

ylabel('---> Amplitude');

xlabel('---> t');

OUTPUT WAVEFORM

SCIENSITY

Friday 6 January 2012

mat lab programs and output

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