Amplitude Modulation using MATLAB

Amplitude modulation (AM) is a modulation technique utilized in electronic communication, most ordinarily for transmitting data by means of a carrier wave. In amplitude modulation, the amplitude that is the signal quality of the carrier wave differs with respect to that of the message signal being transmitted.

Amplitude modulation in MATLAB can be achieved by using the ammod() function. 

ammod()

Syntax : y = ammod(x, Fc, Fs, ini_phase, carramp) 
Parameters :

• x : amplitude signal
• Fc : carrier signal frequency
• Fs : sampling frequency
• ini_phase : initial phase in the modulated signal y in radians
• carramp : carrier amplitude of the modulated signal

Returns : amplitude modulated (AM) signal 

Example: Amplitude modulation of a sine wave with only 3 parameters.

MATLAB

% carrier Frequency
Fc = 200;

% sampling frequency
Fs= 4000;

% time Duration
t = (0 : 1 / Fs : 1);

% sine Wave with time duration of 't'
x = sin(2*pi*t);

% Amplitude Modulation
y = ammod(x, Fc, Fs);

plot(y);
title('Amplitude Modulation');
xlabel('Time(sec)');
ylabel('Amplitude');

Output :