Downsampled STFT Filter Banks

We now look at STFT filter banks which are downsampled by the factor $R>1$ . The downsampling factor $R$ corresponds to a hop size of $R$ samples in the overlap-add view of the STFT. From the filter-bank point of view, the impact of $R>1$ is aliasing in the channel signals when the lowpass filter (analysis window) is less than ideal. When the conditions for perfect reconstruction are met, this aliasing will be canceled in the reconstruction (when the filter-bank channel signals are remodulated and summed).