Produção Nacional
Revisado por pares
A new delayless subband adaptive filter structure
1999; Institute of Electrical and Electronics Engineers; Volume: 47; Issue: 6 Linguagem: Inglês
10.1109/78.765127
ISSN1941-0476
AutoresRicardo Merched, Paulo S. R. Diniz, Mariane R. Petraglia,
Tópico(s)Speech and Audio Processing
ResumoAdaptive subband techniques have been developed to reduce complexity and slow convergence problems of the traditional fullband high-order adaptive filters. Some of the disadvantages often encountered in most of the proposed architectures are the effect of aliasing associated with the multirate structure, which is a source of error in the modeling of the unknown system, and the delay introduced in the signal path. We present a new delayless maximally decimated structure where the optimal subband filters are related to the wideband system in a closed form. They make use of a special DFT analysis filterbank where the polyphase components of the prototype filter represent fractional delays so that there is no need for adaptive cross-filters, and the unknown system can modeled perfectly in a closed-loop scheme. We interpret the proposed structure as a special case of a block adaptive filter with lower computational complexity than the conventional fullband LMS algorithm. Some computer simulations are presented in order to verify the good features of the proposed structure.
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