How does sinc interpolation work? - Mathematics Stack Exchange Convolution with sinc pulses What we want to do to reconstruct the signal is a convolution between the samples and scaled and shifted versions of sinc This technique is known as Whittaker–Shannon interpolation: " This is equivalent to filtering the impulse train with an ideal (brick-wall) low-pass filter with gain of 1 (or 0 dB) in the passband