使用近似無頻疊失真餘弦調變濾波器組之次頻帶適應性濾波

Abstract

在此篇論文中，我們使用近似無頻疊失真特性的餘弦調變濾波器組來達成次頻帶適應性濾波。我們證明了即使加入次頻帶濾波器，餘弦調變濾波器組仍然保有近似無頻疊失真的特性。在早期的設計當中，實係數的餘弦調變濾波器組，其無頻疊失真的特性通常會因為加入了次頻帶濾波器而遭到破壞。此餘弦調變濾波器組為實係數，因此濾波和次頻帶調適所需的運算複雜度少於複數濾波器組。數值模擬的結果展示其近似無頻疊失真的特性和快速的收斂速度。

In this paper, we use a class of cosine modulated filterbank (CMFB) with approximately reconstruction property for subband adaptive filtering. We show that even after the subband filters are included, the CMFB maintains the approximately alias-free property. In earlier designs, when the filterbank has real coefficients, the alias-free property is usually destroyed after subband filters are inserted. The CMFB has real coefficients and the computational complexity for filtering and subband adaptation is less than that of complex-valued filterbanks. Numerical simulations will be given to demonstrate its approximately alias-free property and fast convergence.