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Sinc interpolation

Nasser M. Abbasi

Feb 18 2010 compiled on — Wednesday July 06, 2016 at 08:34 AM
This demonstration illustrates the use of the Sinc interpolation formula to reconstruct a continues signal from its samples. The formula provides exact reconstructions for signals that are bandlimited and whose samples where obtained using the required Nyquist sampling frequency in order to eliminate aliasing in the reconstruction of the signal from its samples.

A number of continues signals are available to select from to apply the interpolation formula on. By increasing the sampling frequency a more accurate reconstruction of the continues function would result.

The original signal is shown in blue colored solid line, and the sample locations are shown using the red circles. The reconstructed signal is shown using the dotted magenta colored line and is superimposed on the original signal to make it easier to see the effect of increasing the sampling frequency on the reconstruction of the original signal from its samples.

Since a limited number of samples is used in this demonstration, there will be some error remaining in the reconstruction even at a higher sampling frequency than the Nyquist frequency. The absolute error (point by point error) between the original signal and the reconstructed signal is plotted to allow one to observe how the error decreases as the sampling rate increases.