(New page: == Sampling theorem== Here is a signal, x(t) with X(w) = 0 when |W| > Wm. With sampling period, T, samples of x(t),x(nT), can be obtained from x(t), where n = 0 +-1, +-2, .... The sa...) |
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Revision as of 16:25, 9 November 2008
Sampling theorem
Here is a signal, x(t) with X(w) = 0 when |W| > Wm.
With sampling period, T, samples of x(t),x(nT), can be obtained from x(t), where n = 0 +-1, +-2, ....
The sampling frequency is $ frac{2 * / pi}{T} $. It is called Ws.
If Ws is greater than 2Wm, x(t) can be recovered from its samples.
Here, 2Wm is called the "Nyquist rate".
To recover, first we need a filter with amplited T when |W| < Wc.
Wc has to exist between Wm and Ws-Wm.
