In this section, we will derive the Fourier dual of the
Constant OverLap-Add (COLA) condition for STFT analysis windows
(discussed in §7.1). Recall that for perfect reconstruction
using a hop-size of
samples, the window must be
. We
will find that the equivalent frequency-domain condition is that the
window transform must have spectral zeros at all frequencies
which are a nonzero multiple of
. Following established
nomenclature for filter banks, we will say that such a window
transform is
.