Analysis and Fast In1plementation of Oversampled Modulated Filter Banks
Stephan Weiss · 2002
Abstract Qyersampled modulated filter banks (OSFBs) are popularly employed for a 1mmbcr 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 factorize the OSFB into filter components depending on the prototype filter, and the modulating transform. Based on a state-space representation of this derived polyphase factorization, signal flow graphs can be obtained which permit a very simple and efficient OSFB impfornentation. The analysis is performed for a number of different classes of OSFBs, and a comparison to existing methods is drawn.