Time scaling matlab code

%>>>>>>>>>>>>>>>>>>>> Tuterial on AM Modulation <<<<<<<<<<<<<<<<<<<<<<<<<<

clc;

close all;

clear all;

%XXXXXXXXXXXXXXXXXXXXXXXXXXX Define AM modulation Index XXXXXXXXXXXXXXXXXXX

disp(' example: m=1 means 100% modulation');

m=input(' Enter the value of modulation index (m) = ');

%m=1; % for 100% modulation

if (0>m||m>1)

error('m may be less than or equal to one and geter than to zero');

end

%XXXXXXXXXXXXXXXXX modulating signal generation XXXXXXXXXXXXXXXXXXXXXXXXXX

Am =input('Enter the value of amplitude modulation =');

%Am=5; % Amplitude of modulating signal

fa=2000; % Frequency of modulating signal

Ta=1/fa; % Time period of modulating signal

t=0:Ta/999:6*Ta; % Total time for simulation

ym=Am*sin(2*pi*fa*t); % Equation of modulating signal

figure(1)

subplot(3,1,1);

plot(t,ym), grid on;% Graphical representation of Modulating signal

%axis ([0 1 -5 5]);

title ( ' Modulating Signal ');

xlabel ( ' time(sec) ');

ylabel (' Amplitud(volt) ');

%XXXXXXXXXXXXXXXXXXXXX carrier signal generation XXXXXXXXXXXXXXXXXXXXXXXXXX

Ac=Am/m;% Amplitude of carrier signal [ where, modulation Index (m)=Am/Ac ]

fc=fa*10;% Frequency of carrier signal

Tc=1/fc;% Time period of carrier signal

yc=Ac*sin(2*pi*fc*t);% Eqation of carrier signal

subplot(3,1,2);

plot(t,yc), grid on;% Graphical representation of carrier signal

title ( ' Carrier Signal ');

xlabel ( ' time(sec) ');

ylabel (' Amplitud(volt) ');

%XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX AM Modulation XXXXXXXXXXXXXXXXXXXXXXXXXXXXX

y=Ac*(1+m*sin(2*pi*fa*t)).*sin(2*pi*fc*t); % Equation of Amplitude

%modulated signal

subplot(3,1,3);

plot(t,y);% Graphical representation of AM signal

title ( ' Amplitude Modulated signal ');

xlabel ( ' time(sec) ');

ylabel (' Amplitud(volt) ');

grid on;

%>>>>>>>>>>>>>>>>>>>>>> end of program <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

Question

How to do time scaling in the full AM modulation?

[dpb]

Dunno. What do you mean by "time scaling", precisely?

[ong jia eek]

I want to key in an value of frequency that no matter how much is the frequency, the graph only show 2 cycle

[KALYAN ACHARJYA]

example: m=1 means 100% modulation
 Enter the value of modulation index (m) = 0.2
Enter the value of amplitude modulation =4

Where is 2 cycle?

Answer 1

[Neeraj Kaberpanthi]

Hi,

please refer this corrected code

I have added a new variable 'n' for the number of cycles required @ line number 14 and used it @ line number 18.

%>>>>>>>>>>>>>>>>>>>> Tuterial on AM Modulation <<<<<<<<<<<<<<<<<<<<<<<<<<
clc;
close all;
clear all;
%XXXXXXXXXXXXXXXXXXXXXXXXXXX Define AM modulation Index XXXXXXXXXXXXXXXXXXX
disp(' example: m=1 means 100% modulation');
m=input(' Enter the value of modulation index (m) = ');
%m=1; % for 100% modulation
if (0>m||m>1)
error('m may be less than or equal to one and geter than to zero'); 
end
%XXXXXXXXXXXXXXXXX modulating signal generation XXXXXXXXXXXXXXXXXXXXXXXXXX
Am =input('Enter the value of amplitude modulation =');
n=input('Enter number of cycles = '); % input for number of modulationd signal cycles
%Am=5; % Amplitude of modulating signal
fa=2000; % Frequency of modulating signal
Ta=1/fa; % Time period of modulating signal
t=0:Ta/999:n*Ta; % Total time for simulation
ym=Am*sin(2*pi*fa*t); % Equation of modulating signal
figure(1) 
subplot(3,1,1); 
plot(t,ym), grid on;% Graphical representation of Modulating signal
%axis ([0 1 -5 5]);
title ( '  Modulating Signal   ');
xlabel ( ' time(sec) ');
ylabel (' Amplitud(volt)   ');
%XXXXXXXXXXXXXXXXXXXXX carrier signal generation XXXXXXXXXXXXXXXXXXXXXXXXXX
Ac=Am/m;% Amplitude of carrier signal [ where, modulation Index (m)=Am/Ac ]
fc=fa*10;% Frequency of carrier signal
Tc=1/fc;% Time period of carrier signal
yc=Ac*sin(2*pi*fc*t);% Eqation of carrier signal
subplot(3,1,2);
plot(t,yc), grid on;% Graphical representation of carrier signal
title ( '  Carrier Signal   ');
xlabel ( ' time(sec) ');
ylabel (' Amplitud(volt)   ');
%XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX AM Modulation XXXXXXXXXXXXXXXXXXXXXXXXXXXXX 
y=Ac*(1+m*sin(2*pi*fa*t)).*sin(2*pi*fc*t); % Equation of Amplitude
%modulated signal
subplot(3,1,3);
plot(t,y);% Graphical representation of AM signal
title ( '  Amplitude Modulated signal  ');
xlabel ( ' time(sec) ');
ylabel (' Amplitud(volt)   ');
grid on;
%>>>>>>>>>>>>>>>>>>>>>> end of program <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

--------------------------------------------- Output----------------------------------

example: m=1 means 100% modulation

Enter the value of modulation index (m) = 0.5

Enter the value of amplitude modulation =1

Enter number of cycles = 2

Hope it will help you

[Sk Group]

Time Scaling in MATLAB (Code + Output) https://www.swebllc.com/time-scaling-in-matlab-code-output/

[Walter Roberson]

That code does not do time scaling at all, and it contains several useless statements in it.

Answer 2

[Sk Group]

Time Scaling in MATLAB (Code + Output)

For detailed post with complete code visit: https://www.swebllc.com/time-scaling-in-matlab-code-output/