Uniform Modulated Filterbank 2.6 2002/10/24 2005/10/06 11:14:49.323 GMT-5 Phil Schniter schniter@ee.eng.ohio-state.edu Michael Haag mjhaag@rice.edu Phil Schniter schniter@ee.eng.ohio-state.edu A modulated filterbank is composed of analysis branches which: Modulate the input to center the desired sub-band at DC Lowpass filter the modulated signal to isolate the desired sub-band Downsample the lowpass signal The synthesis branches interpolate the sub-band signals by upsampling and lowpass filtering, then modulate each sub-band back to its original spectral location (see ).

In M-branch critically-sampled uniformly-modulated filterbanks, the kth branch has a modulation frequency of ± ω k 2 M k radians , a lowpass cutoff frequency of M radians, and a downsampling/upsampling factor of M. The most common way to implement this type of uniform modulated filterbank is through the use of polyphase filterbanks and DFTs.