2018 Volume 15 Issue 8 Pages 20180007
The parallel sampling structure of hybrid filter bank (HFB) has been considered as a promising candidate for realizing analog-to-digital conversion with high speed and high resolution simultaneously. However, the HFB design faces a challenge of accurately approximating the ideal synthesis filter frequency responses, which are discontinuous when the widely-adopted analysis filters are used. In this work, we analyze the origin of the ideal synthesis filter discontinuities. To address the discontinuity problem, we propose a novel oversampling scheme, i.e., artificially modifying the analysis filter frequency responses in the oversampling band. Performance evaluation reveals that the proposed oversampling scheme can significantly improve the HFB’s reconstruction accuracy, while avoiding the existing methods’ demerits such as the ill-conditioned coefficient matrix and the large reconstruction error in the oversampling band.