exam

lear;
clc;
close all;

f1 = 500;
f2 = 1000;
fc = 5000;
fs = 50*fc;

t= [0 : 1/fs : 10/fc];

signal = 5*(1+0.5*cos (2*pi*f1.*t) + 0.5*cos (2*pi*f2.*t)).*cos(2*pi*fc.*t);

subplot(2,1,1);
plot (t, signal, 'linewidth', 1.5, 'g');
xlabel('time [s]');
ylabel('Amplitude [V]');
title('Time domain plot for AM Signal');
grid on;

Nsamps = length(signal);
signal_fft = abs(fft(signal));
signal_fft = signal_fft(1:Nsamps/2);
f = fs*(0:Nsamps/2-1)/Nsamps;

subplot(2,1,2);
plot(f, signal_fft, 'linewidth', 2, 'r');
xlim([0 10e3]);
xlabel('Frequency (Hz)');
ylabel('Amplitude');
title('Frequency domain plot for AM Signal');
grid on;