Help me to compute the power spectrum for a sampled signal using Matlab

[MATLAB]

Hi!
I have a question on MATLAB as follows:
The signal x(t) = sin(ω1t) , given ω1 = 5 , is sampled at 7 samples/sec during8 sec. Compute the power spectrum for the sampled signal.
Can any body help me with that?
thanks

 

[hr_rezaee]

Question on MATLAB

hi
see fft() help. it is useful.

 

[claudiocamera]

Question on MATLAB

Unless some adjustment in frequency axis, you can start trying the code below.

>> w1=5;
>> t=0:1/7:8;
>> ws=7;
>> x=sin(w1*t);
>> Xw=abs(fftshift(fft(x)));
>> Ws=[-28:28]*ws;
>> plot(Ws,Xw)

 

[shirzadi]

Re: Question on MATLAB

correct Matlab Code is:

>> w1=5;
>> t=0:1/7:8;
>> ws=7;
>> x=sin(2*pi*w1*t);
>> Xw=abs(fftshift(fft(x)));
>> Ws=[-28:28]*ws;
>> plot(Ws,Xw)