Design of Time–Frequency Optimal Three-Band Wavelet Filter Banks with Unit Sobolev Regularity Using Frequency Domain Sampling

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• 作者：Dinesh Bhati ; Manish Sharma ; Ram Bilas Pachori…
• 关键词：Dyadic factorization ; Sobolev regularity ; Time–frequency localization ; Vanishing moment ; Cascade algorithm ; Frequency domain sampling
• 刊名：Circuits, Systems, and Signal Processing
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：35
• 期：12
• 页码：4501-4531
• 全文大小：1,369 KB
• 刊物类别：Engineering
• 刊物主题：Electronic and Computer Engineering
  
• 出版者：Birkh盲user Boston
• ISSN：1531-5878
• 卷排序：35

文摘

In this paper, we design three-band time–frequency-localized orthogonal wavelet filter banks having single vanishing moment. We propose new expressions to compute mean and variances in time and frequency from the samples of the Fourier transform of the asymmetric band-pass compactly supported wavelet functions. We determine discrete-time filter of length eight that generates the time–frequency optimal time-limited scaling and wavelet functions using cascade algorithm. Time–frequency product (TFP) of a function is defined as the product of its time variance and frequency variance. The TFP of the designed functions is close to 0.25 with unit Sobolev regularity. Three-band filter banks are designed by minimizing a weighted combination of TFPs of wavelets and scaling functions. Interestingly, empirical results show that time–frequency optimal, filter banks of length nine, designed with the proposed methodology, have unit Sobolev regularity, which is maximum achievable with single vanishing moment. Design examples for length six and length nine filter banks are given to demonstrate the effectiveness of the proposed design methodology.