Block decimated analysis-synthesis filter banks

Analysis-synthesis filter banks with nonuniform subsamplers (block decimators) are introduced, and their design is studied. In such systems, the channel downsamplers and upsamplers are allowed to be nonuniform, which results in a different type of reconstruction problem from that of uniformly subsampled systems. In the present work, it is shown that it is possible to design perfect reconstruction block decimated systems. Because of the decimation structure, however, the frequency domain behavior of the block decimated systems can be very different than that of uniformly subsampled systems. Block decimated systems can be analyzed in two different forms: from a time domain perspective, which results in a set of reconstruction conditions on the system filters; or using an indirect approach in which the system is converted into a uniform band system. Both approaches are described and discussed