A Low-Complexity Uniform and Non-uniform Digital Filter Bank Based on an Improved Coefficient Decimation Method for Multi-standard Communication Channelizers

It has been shown in literature that the coefficient decimation (CD) techniques can be efficiently used to realize low complexity finite impulse response (FIR) filters with flexible frequency responses. In this paper, we propose a novel filter bank (FB) design technique based on the combination of the conventional coefficient decimation method (CDM) and the modified coefficient decimation method recently proposed by us. In the proposed FB, subbands of desired bandwidths are obtained by the spectral subtraction of the lowpass and highpass frequency responses obtained after performing CD operations on the prototype filter, using appropriate decimation factors. The proposed FB that provides uniform as well as non-uniform subbands can be used for multi-standard channelization in wireless communication receivers. We show that the proposed FB has a significantly lower complexity along with superior stopband and transition band characteristics when compared with the conventional CDM based progressive decimation filter bank (PDFB). Design example shows that the proposed FB offers 74% reduction in multiplication complexity over the PDFB, when used for non-uniform multi-standard channelization with a fixed frequency channel distribution. If the same FB is used for multi-standard channelization with variable locations of the frequency channels, a substantial 95.67% reduction in multiplication complexity is achieved over the PDFB.