STFT, Rectangular Window, No Overlap

• Perfect reconstruction
• Critically sampled (relies on aliasing cancellation)
• Poor channel isolation ( $\approx 13$ dB)
• Not robust to filter-bank modifications

This is the main critically sampled perfect-reconstruction filter bank implemented by an STFT (other examples involve Portnoff windows, §9.7). ``Filter-bank modifications'' here means modifications introduced as time-varying complex gains applied to the filter-bank channel signals prior to remodulation and summing to reconstruct the signal (Chapter 9). In contrast to this, as discussed in Chapter 8, multiplicative spectral modifications in overlap-add systems having sufficient time-domain zero-padding yield perfect reconstruction of the filtered signal, even when their filter-bank interpretation obviously involves aliasing cancellation among channels in the frequency domain.