Optimized orthonormal wavelet filters with improved frequency separation

Autor(es)

Paiva, Henrique Mohallem ^[1] ; Harrop Galvao, Roberto Kawakami ^[2]

Afiliação do(s) autor(es)

^[1] Mectron Engn Ind & Comercio SA, Sao Jose Dos Campos, SP - Brazil

^[2] Inst Tecnol Aeronaut, Div Engn Eletron, Sao Jose Dos Campos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: DIGITAL SIGNAL PROCESSING; v. 22, n. 4, p. 622-627, JUL 2012.
• Citações Web of Science: 9

Resumo

This paper proposes an optimization-based method to design orthonormal wavelet filters with improved frequency separation. The proposed approach adopts a parameterization of orthogonal filter banks which ensures that the resulting wavelets have at least two vanishing moments. The filter parameters are adjusted by a numerical optimization algorithm in order to minimize a cost function associated to cut-off sharpness. In comparison with standard orthonormal filters, the proposed method is shown to provide better trade-off between frequency selectivity and time resolution. For illustration, the optimized filters are employed in an application example involving the use of a wavelet-packet system identification scheme. As a result, the identification errors are smaller than those obtained by using a non-optimized filter with the same length. (C) 2012 Elsevier Inc. All rights reserved. (AU)

• Processo FAPESP: 06/58850-6 - Diagnóstico, prognóstico e acomodação de falhas em sistemas dinâmicos
• Beneficiário: Takashi Yoneyama
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 11/17610-0 - Monitoramento e controle de sistemas dinâmicos sujeitos a falhas
• Beneficiário: Roberto Kawakami Harrop Galvão
• Modalidade de apoio: Auxílio à Pesquisa - Temático