A new design method to obtain flexible and low complexity uniform filter banks

Coefficient decimation (CD) techniques can be used to obtain variable low pass, high pass and multi-band frequency responses using a single low pass prototype filter. CD techniques have the advantages of low complexity and flexible implementations. In this paper, we present a new design method to obtain uniform filter banks (FBs) using the recently proposed improved coefficient decimation method (ICDM). In the proposed FB design method, algebraic operations such as spectral subtraction, complementary filter operation and frequency response masking are performed on the frequency responses obtained using the ICDM to obtain the desired sub bands in the FB. We show that our FB is a low complexity alternative to the widely used discrete Fourier transform based FB (DFTFB) and the conventional coefficient decimation method based FB (CDFB). The proposed FB has twice the flexibility in terms of the possible number and locations of its sub bands when compared with the DFTFB and CDFB. Design example and the corresponding implementation results show that our FB achieves significant advantages over the DFTFB and CDFB in terms resource utilizations and power consumptions.