Analysis and Fast Implementation of Oversampled Modulated Filter Banks

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Description/Abstract

Oversampled modulated filter banks (OSFBs) are popularly employed for a number of applications such as acoustic echo cancellation in order to reduce the processing complexity of a signal processing algorithm. Hence, an efficient implementation of OSFBs themselves is mandatory. In this paper, a polyphase description is used to remove redundancies in the filter operations and to factorise the OSFB into filter components depending on the prototype filter, and the modulating transform. Based on a state-space representation of this derived polyphase factorisation, signal flow graphs can be obtained which permit a very simple and efficient OSFB implementation. The analysis is performed for a number of different classes of OSFBs, and a comparison to existing methods is drawn.