05-10-2010, 12:32 PM
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A New Delayles s Subband Adaptive Filtering
Algorithm for Active Noise Control Systems
Ali A. Milani, Student Member, IEEE, Issa M. S. Panahi, Senior Member, IEEE, and
Philipos C. Loizou, Senior Member, IEEE
Abstract—
Subband adaptive filtering (SAF) techniques play a
prominent role in designing active noise control (ANC) systems.
They reduce the computational complexity of ANC algorithms,
particularly, when the acoustic noise is a broadband signal and the
system models have long impulse responses. In the commonly used
uniform-discrete Fourier transform (DFT) -modulated (UDFTM)
filter banks, increasing the number of subbands decreases the
computational burden but can introduce excessive distortion,
degrading performance of the ANC system. In this paper, we propose
a new UDFTM-based adaptive subband filtering method that
alleviates the degrading effects of the delay and side-lobe distortion
introduced by the prototype filter on the system performance.
The delay in filter bank is reduced by prototype filter design and
the side-lobe distortion is compensated for by oversampling and
appropriate stacking of subband weights. Experimental results
show the improvement of performance and computational complexity
of the proposed method in comparison to two commonly
used subband and block adaptive filtering algorithms.