Efficient implementation of complex exponentially-modulated filter banks

In Exponentially-ModulatedFilter Bank (EMFB) the complex subfilters are generated from a real-valued prototype filter by multiplying the filter impulse response with complex exponential sequences. This gives the possibility to use block transforms with computationallyfast algorithms. Our definitionfor the EMFB is based on Extended Lapped Transform(ELT).Then we may apply Fast ELTbased algorithms forcosine-modulatedand sine-modulatedfilterbanks (CMFB, SMFB) as basic building blocks in the implementation of this complex filter bank. Alternatively, a modified polyphase structure with 2 branches ( being the sampling rate conversion factor) can be used. The latter structure can be used also with non-perfectreconstruction filter bank designsthat allow some additionaldegreesof freedom in the optimization. In this paper we explore these alternative realization structuresfor CMFBs and SMFBs.

• Type: Conference
• Year: 2003
• Where: ISCAS
• Authors: Juuso Alhava, Ari Viholainen, Markku Renfors
• Keywords: Complex Filter Bank, Filter Bank, Filter Impulse Response, ISCAS 2003