28 Feb
2001
28 Feb
'01
12:27 p.m.
On Wed, 28 Feb 2001, Gabaly, Stephen J wrote:
Actually, you must sample at MORE than twice the highest signal
frequency, and wasn't it Nyquist that proved this?
clint
-----Original Message-----
Some of Shannon's better known known theorems include
the Sampling Theorem, which indicates that a bandwidth-limited
signal can be reconstructed only if sampled at least at twice
the frequency of the highest-frequency spectral content.
Take a 1 Vpp@40Hz Sinewave, highest-frequency spectral content is 40Hz,
sample it at twice this frequency, 80Hz, sample at 0 and 180 degrees (0Vpp
Amplitude), the reconstructed sinewave will be 0Vpp at 0 Hz. Oh well, guess
Shannon's theorem is incorrect...
steve