tailieunhanh - Báo cáo hóa học: " Research Article Phasor Representation for Narrowband Active Noise Control Systems"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Phasor Representation for Narrowband Active Noise Control Systems | Hindawi Publishing Corporation EURASIP Journal on Audio Speech and Music Processing Volume 2008 Article ID 126859 8 pages doi 2008 126859 Research Article Phasor Representation for Narrowband Active Noise Control Systems Fu-Kun Chen 1 Ding-Horng Chen 1 and Yue-Dar Jou1 2 1 Department of Computer Science and Information Engineering Southern Taiwan University 1 Nan-Tai Street Yung-Kang City Tainan County 71005 Taiwan 2 Department of Electrical Engineering ROC Military Academy Feng-Shan City Kaohsiung 83059 Taiwan Correspondence should be addressed to Fu-Kun Chen fkchen@ Received 25 October 2007 Accepted 19 March 2008 Recommended by Sen Kuo The phasor representation is introduced to identify the characteristic of the active noise control ANC systems. The conventional representation transfer function cannot explain the fact that the performance will be degraded at some frequency for the narrowband ANC systems. This paper uses the relationship of signal phasors to illustrate geometrically the operation and the behavior of two-tap adaptive filters. In addition the best signal basis is therefore suggested to achieve a better performance from the viewpoint of phasor synthesis. Simulation results show that the well-selected signal basis not only achieves a better convergence performance but also speeds up the convergence for narrowband ANC systems. Copyright 2008 Fu-Kun Chen et al. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. INTRODUCTION The problems of acoustic noise have received much attention during the past several decades. Traditionally acoustic noise control uses passive techniques such as enclosures barriers and silencers to attenuate the undesired noise 1 2 . These passive techniques are highly valued for their high attenuation over a broad range of frequency. However they are .