Search in: Word
Vietnamese keyboard: Off
Virtual keyboard: Show
Computing (FOLDOC) dictionary
Nyquist Theorem
Jump to user comments
communications A theorem stating that when an analogue
waveform is digitised, only the frequencies in the waveform
below half the sampling frequency will be recorded. In
order to reconstruct (interpolate) a signal from a sequence of
samples, sufficient samples must be recorded to capture the
peaks and troughs of the original waveform. If a waveform is
sampled at less than twice its frequency the reconstructed
waveform will effectively contribute only noise. This
phenomenon is called "aliasing" (the high frequencies are
"under an alias").