Title :
Analysis of a delayless subband adaptive filter
Author :
Hirayama, Naoki ; Sakai, Hideaki
Author_Institution :
Graduate Sch. of Eng., Kyoto Univ., Japan
Abstract :
An analysis of a delayless subband adaptive digital filter (ADF) structure is presented. In this structure adaptive weights in each subband are computed by the LMS algorithm and then transformed into those in fullband by the Hadamard transform. The conventional subband ADF has transmission delay and aliasing effects associated with the filter bank. However in this manner such defects are avoided while retaining the computational and convergence speed advantages of subband decomposition. In addition the overall transfer function of the novel type of subband ADF is strictly equivalent to that of the Wiener filter for the fullband ADF. Also, a characteristic equation is derived to discuss the stability of the adaptation algorithm. Some numerical results show the good performance of this scheme
Keywords :
Hadamard transforms; Wiener filters; adaptive filters; adaptive signal processing; band-pass filters; computational complexity; digital filters; filtering theory; least mean squares methods; numerical stability; signal sampling; transfer functions; Hadamard transform; LMS algorithm; Wiener filter; adaptation algorithm stability; adaptive weights; aliasing effects; characteristic equation; computational complexity; computational speed; convergence speed; delayless subband adaptive digital filter; filter bank; frequency sampling; fullband; performance; subband decomposition; transfer function; transmission delay; Adaptive filters; Convergence; Delay effects; Digital filters; Equations; Filter bank; Least squares approximation; Stability; Transfer functions; Wiener filter;
Conference_Titel :
Acoustics, Speech, and Signal Processing, 1997. ICASSP-97., 1997 IEEE International Conference on
Conference_Location :
Munich
Print_ISBN :
0-8186-7919-0
DOI :
10.1109/ICASSP.1997.599519
