Sampling (Signal Analysis)

[shyfx]

I am at uni doing electronics and one of our subjects is circuit and signal analysis. We are currently doing the sampling theorem and I am not sure on how this works.

How does one sample a signal then reconstruct it? We are using MATLAB to do this, so we just generate a sampled signal instead of sampling a continuous signal. From there, where do I go?
All I can make out is that I Fourier transform it using FFT in MATLAB, then sample this function, run it through a low pass (ideal rectangle) filter then from there, I can reconstruct it, but I haven't the slightest clue how and I can't gather anythign from my text.
http://www.jhu.edu/~signals/sampling/
I see this website does it.

Any help would be great!!

Thanks
-Mikey

 

[joensd]

Hi Mikey,
am in the same boat here. Just started to have a seminar called "signals&systems" working with Matlab also.
Don´t know much about it but will try to help as far as I can.

All I can make out is that I Fourier transform it using FFT in MATLAB, then sample this function, run it through a low pass (ideal rectangle) filter then from there, I can reconstruct it, but I haven't the slightest clue how and I can't gather anythign from my text.

Seems like you know what´s going on so where is your exact problem.
The formulas of each step?

Can you send me the m-file or did you simulate with Simulink?

greets