MATLAB Simulation Codes and Outputs: 2013

Thursday 19 December 2013

Addition and Multiplication of Two Sequences

close all;
clear all;
clc;
x=input('enter sequence -1');
y=input('enter input sequence-2');
M=length(x);
N=length(y);
subplot(2,2,1);
stem(x);
xlabel('time');
ylabel('amplitude');
title('input sequence-1');
subplot(2,2,2);
stem(y);
xlabel('time');
ylabel('amplitude');
title('input sequence-2');
if M>N
z=x+[y,zeros(1,M-N)];
a=x.*[y,zeros(1,M-N)];
else
z=[x,zeros(1,N-M)]+y;
a=[x,zeros(1,N-M)].*y;
end;
subplot(2,2,3);
stem(z);
xlabel('time');
ylabel('amplitude');
title(' Addition of input sequences");
subplot(2,2,4);
stem(a);
xlabel('time');
ylabel('amplitude');
title('multiplication of input sequences ');

Output:
sequence -1[1 4 8 6]
enter input sequence-2[1 6 8 9]

Sinc funtion and Triangular function

close all;
clear all;
clc;
t=-4:0.1:4;
x=sinc(pi*t);
subplot(2,1,1);
plot(x);
xlabel('time');
ylabel('amplitude');
title('sinc function');
y=0:0.5:2;
for j=0:3
x=(4*j)+y;
subplot(2,1,2);
plot(x,y);
hold on;
end;
for k=0:3
x=(4*k)-y;
subplot(2,1,2);
plot(x,y);
hold on;
end;
hold off;

Output:

Program for Impulse Function and Step function Generation

close all;
clear all;
clc;
n=[-5:5];
i=imp_scr(0,-5,5);
subplot(2,1,1);
stem(n,i);
xlabel('time');
ylabel('amplitude');
title('impulse function');
s=step_scr(0,-5,5);
subplot(2,1,2);
plot(n,s);
xlabel('time');
yalbel('amplitude');
title('step sequence');
%user defined functons

%for imp_scr
function[x,n]=imp_scr(no,n1,n2);
n=[n1:n2];
x=[(n-n0)==0];

%for step_scr
function[x,n]=step_scr[n0,n1,n2];
n=[n1:n2];
x=[(n-n0)>=0];

Note: the user has to type the user defined functions in a new window and save them with the exact same names of imp_scr and step_scr if the user defined functions are to work
The files are to be saved in the same directory as the original file.

Program for Ramp Function and Sequence

close all;
clear all;
clc;
t=0:1:25;
r=t;
subplot(2,1,1);
plot(t,r);
xlabel('time');
ylabel('amplitude');
title('ramp function');
subplot(2,1,2);
stem(t,r);
xlabel('time');
ylabel('amplitude');
title('ramp sequence');

Output:

Basic Waves in Discrete Time Domain

close all;
clear all;
clc;
t=0:0.001:2;
f=1;
w=2*pi*f;
a=sint(w*t);
subplot(2,2,1);
stem(t,a);
xlabel('time');
ylabel('amplitude');
title('sinusoidal signal');
b=cos(w*t);
subplot(2,2,2);
stem(t,b);
xlabel('time');
ylabel('amplitude');
title('co-sinusoidal signal');
c=square(w*t);
subplot(2,2,3);
stem(t,c);
xlabel('time');
ylabel('amplitude');
title('square signal');
d=sawtooth(w*t);
subplot(2,2,2);
stem(t,d);
xlabel('time');
ylabel('amplitude');
title('sawtooth signal');

Various Basic Signals

close all;
clear all;
clc;
t=0:0.001:2;
f=1;
w=2*pi*f;
a=sint(w*t);
subplot(2,2,1);
plot(t,a);
xlabel('time');
ylabel('amplitude');
title('sinusoidal signal');
b=cos(w*t);
subplot(2,2,2);
plot(t,b);
xlabel('time');
ylabel('amplitude');
title('co-sinusoidal signal');
c=square(w*t);
subplot(2,2,3);
plot(t,c);
xlabel('time');
ylabel('amplitude');
title('square signal');
d=sawtooth(w*t);
subplot(2,2,2);
plot(t,d);
xlabel('time');
ylabel('amplitude');
title('sawtooth signal');

Output:

Basic Operations on Matrices Matlab Code

clear all;
close all;
clc;
a=input('enter matrix A:');
b=input('eneter matrix B:');
c=input('enter Matrix C:');
disp('the size of matrix A is :');
disp(size(a));
disp('the size of matrix B is :');
disp(size(b));
disp('the size of matrix C is :');
disp(size(c));
disp('the addition of matrices A & B is:');
disp(a+b);
disp('the substraction of matrices A & B is :');
disp(a-b);
disp('the element by element multiplication of A & B is:');
disp(a.*b);
disp('The trace of matrix C is :');
disp(trace(c));
disp('the determinant of the matrix C is :');
disp(det(c));
disp ('the inverse of matrix C is :');
disp(inv(c));
disp(' the rank of matrix C is :');
disp(rank(c));

Outputs if the specied inputs as given below are:

Matrix A : [1 2;3 4]
Matrix B : [3 4;5 6]
Matrix C: [1 2;3 4]

The size of matrix A is
2 2
The size of matrix B is
2 2
The size of matrix c is
2 2
the addition of matrices A & B is: 4 6
8 10
the substraction of matrices A & B is : -2 -2
-2 -2

the element by element multiplication of A & B is: 3 8
15 24

The trace of matrix C is : 5

the determinant of the matrix C is : -2

the inverse of matrix C is : -2.000 1.000
. 1.5000 -0.5000

the rank of matrix C is : 2

Tuesday 24 September 2013

Fm Modulation Code

the Program for coding Freequency Modulation is

clc;
fs=1000;
fc=100;
t=[0:fs]/fs;
k=50;
x=sin(2*pi*t);
subplot(3,1,1);
plot(t,x);
title('message sigal');
xlabel('time');
ylabel('amplitude');
y=fmmod(x,fc,fs,k);
subplot(3,1,2);
plot(t,y);
xlabel('time');
ylabel('amplitude');
title('modulated signal');
z=fmdemod(y,fc,fs,k);
subplot(3,1,3);
plot(t,z);
xlabel('time');
ylabel('amplitude');

title('demodulated wave');

The Output for the above program is:

Wednesday 4 September 2013

DSBSC Modulation Code

The program for DSBSC Modulation is:

clc;
clr;
fs=2;
fc=50;
t=0:0.001:1;
x=sin(2*pi*fs*t);
y=sin(2*pi*fc*t);
subplot(2,2,1);
plot(t,x);
xlabel('time');
ylabel('amplitude');
title('message signal');
subplot(2,2,2);
plot(t,y);
xlabel('time');
ylabel('amplitude');
title('carrier signal');
z=x.*y;
subplot(2,2,3);
plot(z,t);
xlabel('time');
ylabel('amplitude');
title('DSBSC Modulated Waveform');
d=z./y;
subplot(2,2,4);
plot(t,d);
xlabel('time');
ylabel('amplitude');
title('Demodulated Wave');

The output of the code is given as follows:

Tuesday 6 August 2013

Amplitude modulation Code in Matlab

Program

fs=500;

fc=50;

t=[0:2*fs]/fs;

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

y=ammod(x,fc,fs);

z=fft(y);

f=[0:length(z)-1];

subplot(2,2,1);

plot(t,x);

xlabel('time');

xlabel('Freequency');
ylabel('amplitude');
title('Input Waveform');

subplot(2,2,2);

plot(f,y);

ylabel('amplitude');

title('modulated waveform');

subplot(2,2,3);

plot(f,z);

xlabel('Freequency');

ylabel('amplitude');

title('spectrum diagram');x= ammod(y,fc,fs);

subplot(2,2,4);

plot(t,x);

xlabel('time);

ylabel('amplitude);

title('demodulated waveform)

Output waveforms

SSB Modulator Internal Block Diagram

Internal Block diagram and Connections of SSB Modulator

Non Phase shifted Sinusoidal Input waveform - Message Signal

Non Phase shifted Sinusoidal Input waveform - Carrier Signal

Phase shifted Sinusoidal Input waveform - Message Signal

Phase shifted Sinusoidal Input waveform - Carrier Signal

Spectrum Analyser Block Properties

Spectrum Analyser Output

The Experiment

To perform this experiment first insert four sine wave blocks into the workspace

Then place two sine wave blocks together to a multiplier and the other two to another multiplier

In two of the sime wave blocks connected to the same multiplier change the inital phase reading to 90 degrees as shown in the source block parameters

Connect the outputs of the multipliers to an adder and the output of the adder to a spectrumm analyser

DSBSC using Internal Structure of blocks

DSBSC Internal Structure Block Diagram

Input Sine Wave 1 Parameters - Carrier Wave

Sine Wave Input Paraneters - Message Signal

Spectrum Analyser Output DSBSC

DSBSC

BLOCK DIAGRAM DSBSC MODULATOR

Source Block parameters

Modulator Properties DSBSC

DSBSC Modulated Wave

DSBSC Demodulator Blockset

DSBSC Demodulator Properties

DSBSC Demodulated Waveform

SSB MODULATION

MODULATOR BLOCKSET

SOURCE BLOCK PARAMETERS

MODULATOR PROPERTIES

MODULATED WAVE

DEMODULATION BLOCKSET

DEMODULATOR PROPERTIES WINDOW

DEMODULATED WAVEFORM

Freequency Modulation

FREQUENCY MODULATION

The Blocks required for frequency modulation are:
1.Sine wave Block

2. Frequency Modulation Block

3. Sampling Scope

Connect the blocks as shown in the diagram below

Block Diagram

The parameters for the Modulator along with freequency values and other necessary settings are shown in the diagram below

Modulator properties

The source parameters including frequency of the input sine wave are shown in the picture below

Source block parameters

The output waveform appears in the CRO as:

Modulated waveform

For demodulation connect a FM demodulator block in between the FM modulator block and the sampling scope and connect them as shown in the diagram below.

Demodulator block diagram

With the settings of the source and modulator blocks remaining the same adjust the demodulator to the necessary frequency and other parameters as necessary and as shown in the picture below: