SRGPMAP@grace.dsir.govt.nz (06/13/91)
Here is another theoretical breakthrough. It has been stated that a perfect reconstruction filter for sampled audio has an infinite impulse response, due to the infinitely sharp cut-off required at the Nyquist frequency. However, a finite duration reconstruction filter with an impulse response which is a half sine pulse (at a frequency of fs/2) gives exact reconstruction at the Nyquist frequency.