A novel structure for time-varying FIR filter banks

Perfect reconstruction (PR) time-varying analysis-synthesis filter banks are those in which the filters are allowed to change from one set of PR filter banks to another as the input signal is being processed. Such systems have the property that, in the absence of coding, they faithfully reconstruct every sample of the input. This paper introduces a new structure for exact reconstructing time-varying analysis-synthesis filter banks. This structure consists of the conventional filter bank followed by a time-varying post filter. The new method requires neither the redesign of the analysis sections, nor the use of any intermediate analysis filters during transition periods. It provides a simple procedure for designing time-varying filter banks without the disadvantages of the previous methods