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A nearly optimum linear-phase digital FIR filters design

JOAQUIM, Marcelo Basilio; LUCIETTO, Carlos A. S.
Fonte: ACADEMIC PRESS INC ELSEVIER SCIENCE Publicador: ACADEMIC PRESS INC ELSEVIER SCIENCE
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
36.18%
A new simple method to design linear-phase finite impulse response (FIR) digital filters, based on the steepest-descent optimization method, is presented in this paper. Starting from the specifications of the desired frequency response and a maximum approximation error a nearly optimum digital filter is obtained. Tests have shown that this method is alternative to other traditional ones such as Frequency Sampling and Parks-McClellan, mainly when other than brick wall frequency response is required as a desired frequency response. (C) 2011 Elsevier Inc. All rights reserved.

Propriedades de filtros lineares para sistemas lineares com saltos markovianos a tempo discreto; Properties of linear filters for discrete-time Markov jump linear systems.

Gomes, Maria Josiane Ferreira
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 12/03/2015 Português
Relevância na Pesquisa
46.18%
Este trabalho é dedicado ao estudo do erro de estimação em filtragem linear para sistemas lineares com parâmentros sujeitos a saltos markovianos a tempo discreto. Indroduzimos o conceito de alcançabilidade média para uma classe de sistemas. Construímos um conjunto de matrizes de alcançabilidade e mostramos que o conceito usual de alcan- çabilidade definido através da positividade do gramiano é caracterizado pela definição por posto completo destas matrizes. A alcançabilidade média funciona como condição necessária e suficiente para positividade do segundo momento do estado do sistema, resultado esse que auxilia na caracterização da positividade uniforme da matriz de covariância do erro de estimação. Abordamos a estabilidade de estimadores com a interpretação de que a covariância do erro permanece limitada na presença de erro de qualquer magnitude no modelo do ruído, que é uma característica relevante para aplicações. Apresentamos uma prova de que filtros markovianos são estáveis sempre que o segundo momento condicionado é positivo. Exemplos numéricos encontram-se inclusos.; This work studies linear filtering for discrete-time systems with Markov jump parameters. We introduce a notion of average reachability for these systems and present a set of matrices playing the role of reachability matrices...

Influence of image filters on the reproducibility of measurements of alveolar bone loss

Alves, Wivian Eiras Garcia Wong; Ono, Evelise; Tanaka, Jefferson Luis Oshiro; Medici Filho, Edmundo; De Moraes, Luiz César; De Moraes, Mari Eli Leonelli; Castilho, Julio Cezar de Melo
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 415-420
Português
Relevância na Pesquisa
36.28%
The reproducibility of measurements of alveolar bone loss on radiographs may be a problem on epidemiologic studies, as they are based on comparisons of the diagnosis of various examiners. The aim of the present research paper was to assess the inter- and intra-examiner reproducibility of measurements of the interproximal alveolar bone loss on non-manipulated digital radiographs and after the application of image filters. Five Oral Radiologists measured the distance between the cementoenamel junction (CEJ) to the alveolar crest or to the deepest point of the bony defect on 12 interproximal digital radiographs of molars and bicuspids of a dry human skull. The digital manipulation and the linear measurements were obtained with the Trophy Windows software (Throphy®). For each image, six different versions were created: 1) non-manipulated; 2) bright-contrast adjustment; 3) negative; 4) negative with brightness-contrast adjustment; 5) pseudo-colored; 6) pseudo-colored with brightness-contrast adjustment. In order to prevent interpretation bias because of the repetition of measurements, the examiners measured the radiographs in a random sequence. The two-way ANOVA test at 5% level of significance to compare the means of readings of the same operator with each filter indicated p<0.05 for the majority of operators...

Method validation using weighted linear regression models for quantification of UV filters in water samples

Silva, Claudia Pereira da; Emidio, Elissandro Soares; Rodrigues de Marchi, Mary Rosa
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 221-227
Português
Relevância na Pesquisa
36.24%
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); This paper describes the validation of a method consisting of solid-phase extraction followed by gas chromatography-tandem mass spectrometry for the analysis of the ultraviolet (UV) filters benzophenone-3, ethylhexyl salicylate, ethylhexyl methoxycinnamate and octocrylene. The method validation criteria included evaluation of selectivity, analytical curve, trueness, precision, limits of detection and limits of quantification. The non-weighted linear regression model has traditionally been used for calibration, but it is not necessarily the optimal model in all cases. Because the assumption of homoscedasticity was not met for the analytical data in this work, a weighted least squares linear regression was used for the calibration method. The evaluated analytical parameters were satisfactory for the analytes and showed recoveries at four fortification levels between 62% and 107%, with relative standard deviations less than 14%. The detection limits ranged from 7.6 to 24.1 ng L-1. The proposed method was used to determine the amount of UV filters in water samples from water treatment plants in Araraquara and Jau in sao Paulo...

Design of adaptive analog filters for magnetic front-end read channels

Garrido, Nuno Miguel de Figueiredo
Fonte: Instituto Universitário de Lisboa Publicador: Instituto Universitário de Lisboa
Tipo: Tese de Doutorado
Publicado em //2015 Português
Relevância na Pesquisa
36.22%
Dissertation presented in partial fulfillment of the Requirements for the Degree of Doctor of Science and Information Technologies; Esta tese estuda o projecto e o comportamento de filtros em tempo contínuo de muito-alta-frequência. A motivação deste trabalho foi a investigação de soluções de filtragem para canais de leitura em sistemas de gravação e reprodução de dados em suporte magnético, com custos e consumo (tamanho total inferior a 1 mm2 e consumo inferior a 1mW/polo), inferiores aos circuitos existentes. Nesse sentido, tal como foi feito neste trabalho, o rápido desenvolvimento das tecnologias de microelectrónica suscitou esforços muito significativos a nível mundial com o objectivo de se investigarem novas técnicas de realização de filtros em circuito integrado monolítico, especialmente em tecnologia CMOS (Complementary Metal Oxide Semiconductor). Apresenta-se um estudo comparativo a diversos níveis hierárquicos do projecto, que conduziu à realização e caracterização de soluções com as características desejadas. Num primeiro nível, este estudo aborda a questão conceptual da gravação e transmissão de sinal bem como a escolha de bons modelos matemáticos para o tratamento da informação e a minimização de erro inerente às aproximações na conformidade aos princípios físicos dos dispositivos caracterizados. O trabalho principal da tese é focado nos níveis hierárquicos da arquitectura do canal de leitura e da realização em circuito integrado do seu bloco principal – o bloco de filtragem. Ao nível da arquitectura do canal de leitura...

Influence of image filters on the reproducibility measurements of alveolar bone loss

Alves,Wivian Eiras Garcia Wong; Ono,Evelise; Tanaka,Jefferson Luis Oshiro; Medici Filho,Edmundo; Moraes,Luiz César de; Moraes,Mari Eli Leonelli de; Castilho,Julio Cezar de Melo
Fonte: Faculdade De Odontologia De Bauru - USP Publicador: Faculdade De Odontologia De Bauru - USP
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2006 Português
Relevância na Pesquisa
36.28%
The reproducibility of measurements of alveolar bone loss on radiographs may be a problem on epidemiologic studies, as they are based on comparisons of the diagnosis of various examiners. The aim of the present research paper was to assess the inter- and intra-examiner reproducibility of measurements of the interproximal alveolar bone loss on non-manipulated digital radiographs and after the application of image filters. Five Oral Radiologists measured the distance between the cementoenamel junction (CEJ) to the alveolar crest or to the deepest point of the bony defect on 12 interproximal digital radiographs of molars and bicuspids of a dry human skull. The digital manipulation and the linear measurements were obtained with the Trophy Windows software (Throphy®). For each image, six different versions were created: 1) non-manipulated; 2) bright-contrast adjustment; 3) negative; 4) negative with brightness-contrast adjustment; 5) pseudo-colored; 6) pseudo-colored with brightness-contrast adjustment. In order to prevent interpretation bias because of the repetition of measurements, the examiners measured the radiographs in a random sequence. The two-way ANOVA test at 5% level of significance to compare the means of readings of the same operator with each filter indicated p<0.05 for the majority of operators...

Basilar-Membrane Responses to Broadband Noise Modeled Using Linear Filters With Rational Transfer Functions

Recio-Spinoso, Alberto; Fan, Yun-Hui; Ruggero, Mario A.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
46.25%
Basilar-membrane responses to white Gaussian noise were recorded using laser velocimetry at basal sites of the chinchilla cochlea with characteristic frequencies near 10 kHz and first-order Wiener kernels were computed by cross correlation of the stimuli and the responses. The presence or absence of minimum-phase behavior was explored by fitting the kernels with discrete linear filters with rational transfer functions. Excellent fits to the kernels were obtained with filters with transfer functions including zeroes located outside the unit circle, implying nonminimum-phase behavior. These filters accurately predicted basilar-membrane responses to other noise stimuli presented at the same level as the stimulus for the kernel computation. Fits with all-pole and other minimum-phase discrete filters were inferior to fits with nonminimum-phase filters. Minimum-phase functions predicted from the amplitude functions of the Wiener kernels by Hilbert transforms were different from the measured phase curves. These results, which suggest that basilar-membrane responses do not have the minimum-phase property, challenge the validity of models of cochlear processing, which incorporate minimum-phase behavior.

Efficient coding of natural images with a population of noisy Linear-Nonlinear neurons

Karklin, Yan; Simoncelli, Eero P.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /12/2011 Português
Relevância na Pesquisa
36.31%
Efficient coding provides a powerful principle for explaining early sensory coding. Most attempts to test this principle have been limited to linear, noiseless models, and when applied to natural images, have yielded oriented filters consistent with responses in primary visual cortex. Here we show that an efficient coding model that incorporates biologically realistic ingredients – input and output noise, nonlinear response functions, and a metabolic cost on the firing rate – predicts receptive fields and response nonlinearities similar to those observed in the retina. Specifically, we develop numerical methods for simultaneously learning the linear filters and response nonlinearities of a population of model neurons, so as to maximize information transmission subject to metabolic costs. When applied to an ensemble of natural images, the method yields filters that are center-surround and nonlinearities that are rectifying. The filters are organized into two populations, with On- and Off-centers, which independently tile the visual space. As observed in the primate retina, the Off-center neurons are more numerous and have filters with smaller spatial extent. In the absence of noise, our method reduces to a generalized version of independent components analysis...

Detection of point sources in maps of the cosmic microwave background radiation by means of optimal filters

López-Caniego Alcarria, Marcos
Fonte: Universidad de Cantabria Publicador: Universidad de Cantabria
Tipo: Tese de Doutorado
Português
Relevância na Pesquisa
56.34%
RESUMEN: Cuando observamos el cielo con los instrumentos más avanzados en la frecuencia de las microondas, los fotones que vemos fueron originados en regiones muy diferentes del universo. La mayoría proceden de nuestra propia galaxia (emisión difusa de sincrotrón, free-free y polvo), otros se originan en galaxias y cúmulos de galaxias muy lejanos, y, finalmente, una fracción tendrá su origen en la radiación del Big Bang, conocida como la Radiación del Fondo Cósmico de Microondas. Esta radiación está contaminada por las otras y su separación de ellas de una forma satisfactoria sigue siendo un problema abierto. En esta tesis exploraremos diferentes técnicas basadas en filtros lineales para detectar y separar uno de estos contaminantes, la contribución a la señal que se observa de radio galaxias y galaxias infrarrojas lejanas. Éstas son conocidas como fuentes puntuales porque aparecen como objetos puntuales no resueltos -debido a las típicas resoluciones angulares de los instrumentos usados en los experimentos-. En primer lugar, vamos a estudiar las propiedades de una familia de filtros adaptados para la detección de fuentes puntuales, donde modificamos la escala del filtro y usamos un test de Neyman-Pearson para definir la región de aceptación. En segundo lugar...

Learning non-linear time scales with Kernel γ-Filters

Camps-Valls, Gustavo; Muñoz-Marí, Jordi; Martínez-Ramón, Manel; Requena-Carrión, Jesús; Rojo-Álvarez, José Luis
Fonte: Elsevier Publicador: Elsevier
Tipo: info:eu-repo/semantics/acceptedVersion; info:eu-repo/semantics/article Formato: application/pdf
Publicado em /01/2009 Português
Relevância na Pesquisa
36.24%
A family of kernel methods, based on the γ-filter structure, is presented for non-linear system identification and time series prediction. The kernel trick allows us to develop the natural non-linear extension of the (linear) support vector machine (SVM) γ-filter, but this approach yields a rigid system model without non-linear cross relation between time-scales. Several functional analysis properties allow us to develop a full, principled family of kernel γ-filters. The improved performance in several application examples suggests that a more appropriate representation of signal states is achieved.

An efficient GPU-based implementation of recursive linear filters and its application to realistic real-time re-synthesis for interactive virtual worlds; Uma implementação eficiente de filtros lineares recursivos e sua aplicação a re-síntese realistica em tempo real para mundos virtuais interativos

Trebien, Fernando
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Dissertação Formato: application/pdf
Português
Relevância na Pesquisa
56.33%
Muitos pesquisadores têm se interessado em explorar o vasto poder computacional das recentes unidades de processamento gráfico (GPUs) em aplicações fora do domínio gráfico. Essa tendência ao desenvolvimento de propósitos gerais com a GPU (GPGPU) foi intensificada com a produção de APIs não-gráficas, tais como a Compute Unified Device Architecture (CUDA), da NVIDIA. Com elas, estudou-se a solução na GPU de muitos problemas de processamento de sinal 2D e 3D envolvendo álgebra linear e equações diferenciais parciais, mas pouca atenção tem sido dada ao processamento de sinais 1D, que também podem exigir recursos computacionais significativos. Já havia sido demonstrado que a GPU pode ser usada para processamento de sinais em tempo-real, mas alguns processos não se adequavam bem à arquitetura da GPU. Neste trabalho, apresento uma nova técnica para implementar um filtro digital linear recursivo usando a GPU. Até onde eu sei, a solução aqui apresentada é a primeira na literatura. Uma comparação entre esta abordagem e uma implementação equivalente baseada na CPU demonstra que, quando usada em um sistema de processamento de áudio em temporeal, esta técnica permite o processamento de duas a quatro vezes mais coeficientes do que era possível anteriormente. A técnica também elimina a necessidade de processar o filtro na CPU - evitando transferências de memória adicionais entre CPU e GPU - quando se deseja usar o filtro junto a outros processos...

Tratamiento de imágenes de radar de apertura sintética mediante filtros stack; Synthetic aperture radar image processing using stack filters

Buemi, María Elena
Fonte: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires Publicador: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires
Tipo: info:eu-repo/semantics/doctoralThesis; tesis doctoral; info:eu-repo/semantics/publishedVersion Formato: application/pdf
Publicado em //2012 Português
Relevância na Pesquisa
56.43%
En el tratamiento de imágenes que se apartan del modelo Gaussiano aditivo, en particular aquellas que además exhiben una baja relación se nalruido o presentan ruido impulsivo, la aplicación de filtros lineales generalmente no da buenos resultados, siendo los problemas típicos el borroneo de bordes o una pobre atenuación del ruido. Por otro lado, la aplicación de filtros no-lineales a este tipo de imágenes logra filtrar los valores de los pixels más afectados por el ruido y al mismo tiempo preservar los bordes. Las imágenes de Radar de Apertura Sintética (Synthetic Aperture Radar, SAR en inglés) poseen un tipo de ruido llamado speckle, el cual no es ni Gaussiano ni aditivo, y que posee una baja relación se~nal-ruido. Esto hace que la aplicación de filtros no-lineales resulte atractiva para este tipo de datos. Dentro de los filtros no lineales existe la clase de los filtros stack la cual es muy amplia y permite el diseño de filtros óptimos, desde el unto de vista del Error Absoluto Medio (Mean Absolute Error, MAE en inglés), y además permiten el procesamiento paralelo. Es por estas razones que esta tesis se dedica al estudio de la aplicación de esta clase de filtros a imágenes de Radar de Apertura Sintética. Para la evaluación de la efectividad de los filtros stack se utilizaron imágenes SAR simuladas bajo el modelo G0 e imágenes reales. Este modelo fue adoptado debido a su buen comportamiento para diversos tipos de target y su tractabilidad computacional. Se recurrió a evaluaciones de parámetros estadísticos...

Effect of nonlinear filters on detrended fluctuation analysis

Chen, Z.; Hu, K.; Carpena, P.; Bernaola-Galvan, P.; Stanley, H. E.; Ivanov, P. Ch.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
36.28%
We investigate how various linear and nonlinear transformations affect the scaling properties of a signal, using the detrended fluctuation analysis (DFA). Specifically, we study the effect of three types of transforms: linear, nonlinear polynomial and logarithmic filters. We compare the scaling properties of signals before and after the transform. We find that linear filters do not change the correlation properties, while the effect of nonlinear polynomial and logarithmic filters strongly depends on (a) the strength of correlations in the original signal, (b) the power of the polynomial filter and (c) the offset in the logarithmic filter. We further investigate the correlation properties of three analytic functions: exponential, logarithmic, and power-law. While these three functions have in general different correlation properties, we find that there is a broad range of variable values, common for all three functions, where they exhibit identical scaling behavior. We further note that the scaling behavior of a class of other functions can be reduced to these three typical cases. We systematically test the performance of the DFA method in accurately estimating long-range power-law correlations in the output signals for different parameter values in the three types of filters...

Matrix Factorisation with Linear Filters

Akyıldız, Ömer Deniz
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 07/09/2015 Português
Relevância na Pesquisa
46.12%
This text investigates relations between two well-known family of algorithms, matrix factorisations and recursive linear filters, by describing a probabilistic model in which approximate inference corresponds to a matrix factorisation algorithm. Using the probabilistic model, we derive a matrix factorisation algorithm as a recursive linear filter. More precisely, we derive a matrix-variate recursive linear filter in order to perform efficient inference in high dimensions. We also show that it is possible to interpret our algorithm as a nontrivial stochastic gradient algorithm. Demonstrations and comparisons on an image restoration task are given.; Comment: Submitted

Applying the Z-transform for the static analysis of floating-point numerical filters

Monniaux, David
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 02/06/2007 Português
Relevância na Pesquisa
36.22%
Digital linear filters are used in a variety of applications (sound treatment, control/command, etc.), implemented in software, in hardware, or a combination thereof. For safety-critical applications, it is necessary to bound all variables and outputs of all filters. We give a compositional, effective abstraction for digital linear filters expressed as block diagrams, yielding sound, precise bounds for fixed-point or floating-point implementations of the filters.

Adaptive techniques in signal processing and connectionist models

Lynch, Michael Richard
Fonte: University of Cambridge; Department of Engineering; Christ's College Publicador: University of Cambridge; Department of Engineering; Christ's College
Tipo: Thesis; doctoral; PhD
Português
Relevância na Pesquisa
36.25%
This thesis covers the development of a series of new methods and the application of adaptive filter theory which are combined to produce a generalised adaptive filter system which may be used to perform such tasks as pattern recognition. Firstly, the relevant background adaptive filter theory is discussed in Chapter 1 and methods and results which are important to the rest of the thesis are derived or referenced. Chapter 2 of this thesis covers the development of a new adaptive algorithm which is designed to give faster convergence than the LMS algorithm but unlike the Recursive Least Squares family of algorithms it does not require storage of a matrix with n2 elements, where n is the number of filter taps. In Chapter 3 a new extension of the LMS adaptive notch filter is derived and applied which gives an adaptive notch filter the ability to lock and track signals of varying pitch without sacrificing notch depth. This application of the LMS filter is of interest as it demonstrates a time varying filter solution to a stationary problem. The LMS filter is next extended to the multidimensional case which allows the application of LMS filters to image processing. The multidimensional filter is then applied to the problem of image registration and this new application of the LMS filter is shown to have significant advantages over current image registration methods. A consideration of the multidimensional LMS filter as a template matcher and pattern recogniser is given. In Chapter 5 a brief review of statistical pattern recognition is given...

Influência dos filtros de imagem sobre a reprodutibilidade de medidas da perda óssea alveolar; Influence of image filters on the reproducibility measurements of alveolar bone loss

Alves, Wivian Eiras Garcia Wong; Ono, Evelise; Tanaka, Jefferson Luis Oshiro; Medici Filho, Edmundo; Moraes, Luiz César de; Moraes, Mari Eli Leonelli de; Castilho, Julio Cezar de Melo
Fonte: Universidade de São Paulo. Faculdade de Odontologia de Bauru Publicador: Universidade de São Paulo. Faculdade de Odontologia de Bauru
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; Formato: application/pdf
Publicado em 01/12/2006 Português
Relevância na Pesquisa
36.28%
A reprodutibilidade de medidas da perda óssea alveolar em radiografias pode se tornar um problema em levantamentos epidemiológicos, que são baseados em comparações de diagnóstico de vários observadores. O objetivo neste estudo foi avaliar a reprodutibilidade intra e inter-examinador de medidas da perda óssea interproximal, em radiografias digitais não manipuladas e após a aplicação de diferentes filtros de imagem. Cinco radiologistas avaliaram a distância da junção cemento-esmalte até a crista óssea alveolar ou ponto mais apical do defeito ósseo em 12 radiografias digitais interproximais da região de molares e pré-molares de crânio humano macerado. As manipulações digitais e as medidas lineares foram realizadas no programa de computador do sistema radiográfico (Throphy®). Para cada imagem foram criadas seis diferentes versões: 1) não manipulada digitalmente; 2) manipulada por ajuste de brilho e contraste; 3) negativo; 4) negativo com ajuste de brilho e contraste; 5) pseudo-colorida; 6) pseudo-colorida com ajuste de brilho e contraste. Para prevenir tendências da mesma leitura pela avaliação repetida das radiografias, determinou-se uma ordem para a interpretação das imagens. O teste ANOVA fator duplo sem repetição...

Convergence of adaptive morphological filters in the context of Markov chains

Chen, Yidong
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Dissertação
Português
Relevância na Pesquisa
36.19%
A typical parameterized r-opening *r is a filter defined as a union of openings by a collection of compact, convex structuring elements, each of which is governed by a parameter vector r. It reduces to a single parameter r-opening filter by a set of structuring elements when r is a scalar sizing parameter. The parameter vector is adjusted by a set of adaptation rules according to whether the re construction Ar derived from <3>r correctly or incorrectly passes the signal and noise grains sampled from the image. Applied to the signal-union-noise model, the optimization problem is to find the vector of r that minimizes the Mean-Absolute-Error between the filtered and ideal image processes. The adaptive r-opening filter fits into the framework of Markov processes, the adaptive parameter being the state of the process. For a single parameter r-opening filter, we proved that there exists a stationary distribution governing the parameter in the steady state and convergence is characterized in terms of the steady-state distribution. Key filter properties such as parameter mean, parameter variance, and expected error in the steady state are characterized via the stationary distribution. Steady-state behavior is compared to the optimal solution for the uniform model...

Optimizing FIR Approximation for Discrete-Time IIR Filters

Yamamoto, Yutaka; Anderson, Brian; Nagahara, Masaaki; Koyanagi, Yoko
Fonte: Institute of Electrical and Electronics Engineers (IEEE Inc) Publicador: Institute of Electrical and Electronics Engineers (IEEE Inc)
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
36.31%
Finite-impulse response (FIR) filters are often preferred to infinite-impulse response (IIR) filters because of their various advantages in respect of stability, phase characteristic, implementation, etc. This letter proposes a new method to approximate an IIR filter by an FIR filter, which directly yields an optimal approximation with respect to the H∞ error norm. We show that this design problem can be reduced to a linear matrix inequality. We will also make a comparison via a numerical example with an existing method, known as the Nehari shuffle.

Design of Linear Phase IIR Filters with Flat Magnitude Response using Complex Coefficients Allpole Filters

Fernandez Vazquez,Alfonso; Jovanovic Dolecek,Gordana
Fonte: Centro de Investigación en computación, IPN Publicador: Centro de Investigación en computación, IPN
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2007 Português
Relevância na Pesquisa
36.36%
This paper presents a new method for the design of linear phase IIR filters with flat magnitude response. The method is based on the design of flat digital allpole filters with complex coefficients. Depending on the parity of the allpole filter order the resulting IIR filter have either real or complex coefficients. The parameters of the design are the same as in traditional IIR filter design, i.e., passband and stopband frequencies, ωp and ωs, passband droop Ap , and stopband attenuation As . Several design examples are provided to illustrate the method. In addition, a design of linear phase modified two-band IIR filter banks and a design of stable IIR filter with an improved group delay are presented as two applications of the proposed method.