Fourier Transform of a random Signal

t = 0 : 0.001 : 2;

x = (2*(exp(-4*t))).*(cos(10*t).*unit(t))

subplot(2,1,1)
plot(t,x)
grid

I wrote such a code for this signal, but I don't know how to get the fourier transform of this signal. Thank you very much in advance for your help.

Answer 1

[Sulaymon Eshkabilov]

Hi,

Here is the complete code:

t = 0 : 0.001 : 2;
x = (2*(exp(-4*t))).*(cos(10*t).*heaviside(t));
L= numel(x);
Y = fft(x);
M2 = abs(Y/L);
M1 = M2(1:L/2+1);
M1(2:end-1) = 2*M1(2:end-1);
dt=.001;
Fs = 1/dt;
f = Fs*(0:(L/2))/L;
subplot(2,1,1)
plot(t,x)
grid on
subplot(212)
plot(f, abs(M1))
xlim([0, 50]), grid on
xlabel('f, [Hz]')
ylabel('|X|')