A delayless subband active noise control system for wideband noise control

In this paper, we present an efficient noise control algorithm based on the delayless subband adaptive filter. The algorithm reduces the computational complexity of the delayless subband filter by decomposing the secondary pa th response into a set of subband functions. In this new algorithm, the fil tered reference signal is generated for each subband by using a short impul se response filter that models the secondary path transfer function in a su bband-decomposed form. Computational efficiency of the presented method ori ginates from the fact that the filtering process occurs only in one subband for each reference input sample. Furthermore, computational efficiency is enhanced when the presented algorithm is combined with an online identifica tion of the secondary path transfer function. We also propose a frequency-d omain implementation of the presented algorithm. In this implementation, it is shown that the computational complexity is further reduced by employing the block-processing approach.