Title :
Block implementation of a synchronized learning algorithm in adaptive lattice filters
Author :
Tokui, Naoki ; Nakayama, Keisuke ; Hirano, Akira
Author_Institution :
Dept. of Electr. Eng., Ishikawa Nat. Coll. of Technol., Japan
Abstract :
In order to achieve fast convergence and less computation for adaptive filters, a joint method combining a whitening process and the NLMS algorithm is a hopeful approach. However, updating the filter coefficients is not synchronized with the reflection coefficient updating, resulting in unstable behavior. We analyze the effects of this, and propose the "synchronized learning algorithm" to solve this problem. The synchronous error between them is removed, and fast convergence and small residual error are obtained. This algorithm, however, requires O(ML) computations, where M is an adaptive filter length, and L is a lattice predictor length. It is still large compared with the NLMS algorithm. In order to achieve less computation while the fast convergence is maintained, a block implementation method is proposed. The reflection coefficients are updated at some period, and are fixed during this interval. The proposed block implementation can be effectively applied to parallel form adaptive filters, such as sub-band adaptive filters. Simulation using speech signals shows that the learning curve of the proposed block implementation is a little slower than our original algorithm, but can save computational complexity.
Keywords :
adaptive filters; computational complexity; convergence of numerical methods; filtering theory; lattice filters; least mean squares methods; synchronisation; NLMS algorithm; VLSI technology; adaptive filters; adaptive lattice filters; block implementation; computational complexity; filter coefficient updating; lattice predictor length; learning curve; reflection coefficient updating; speech signal; subband filters; synchronized learning algorithm; whitening process; Adaptive filters; Algorithm design and analysis; Convergence; Educational institutions; Information filtering; Information filters; Lattices; Reflection; Telecommunication computing; Transversal filters;
Conference_Titel :
Acoustics, Speech, and Signal Processing, 2003. Proceedings. (ICASSP '03). 2003 IEEE International Conference on
Print_ISBN :
0-7803-7663-3
DOI :
10.1109/ICASSP.2003.1201690