Sampling, Reconstruction of Unsampled Signal.
The original unsampled signal can be recovered from the samples by
passing the samples through a low pass filter with a bandwidth of
half the sampling frequency. In the applet below, the unsampled signal
which is a sine in this case
is in gray, samples are in magenta, the response of the filter to the
first 5 samples are shown by the sinc functions in orange, yellow, green,
cyan and pink, and the sum of the responses is in red. The parameter
BW is the bandwidth of the ideal low pass filter. The applet
illustrates the effect of the sampling time and filter bandwidth on the
eg parameters (1.0, 5.0, 0.4, 2.5, na, na, na, na, na, 1.0) show
that when the bandwidth is half the sampling frequency, the sum
of the sincs is equal to the sampled signal in the range of t where the included sincs are dominant.
Return to main page
Return to page index
© 2000 Cuthbert A. Nyack.