A novel channelized FB architecture with narrow transition bandwidth based on CEM FRM

Abstract

The two key requirements of channelized filter bank in the design of a digital receiver are low computational complexity and reconfigurability. Modulated discrete Fourier transform (MDFT) filter bank permits sub-channel with linear phase characteristics and provides high degree of computational efficiency. However, with sub-channel exhibiting narrow transition bandwidth in MDFT filter bank, the length of the prototype filter becomes long prohibitively, which can reduce the computational efficiency. It is well known that the frequency response masking (FRM) provides an attractive technique for the realization of digital filters with very narrow transition bandwidth. In this paper, the FRM digital filter design technique and another important technique named complex-exponential modulation (CEM) are exploited and applied to the design of a novel cascaded channelized filter bank to realize selective sub-channel with very narrow transition bandwidth. A simulation is provided to illustrate the design of the proposed CEM filter bank. It is shown that the resulting filter bank entails less computational complexity substantially and reduces multiplier resource consumption comparing to the conventional MDFT filter bank.