• Title, Summary, Keyword: Digital filter

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On the Design and Properties of Wave Digital Filter (Wave Digital Filter의 설계 및 특성에 관한 연구)

  • 김인식;김정선
    • Proceedings of the Korean Institute of Communication Sciences Conference
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    • pp.56-60
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    • 1983
  • There has been a great amount of interest in the design of digital filters with low sensitivity to coefficient variations. Especiaily the wave digital filter modeled after analog IC ladder filter has been studied to have low-cocfficient-sensitivity properties. This paper examined the design of the wave digital filter and how the sensitivity and roundoff noise porperty arises. As a result of computer simulation the implementation of the digital filter was possible with a lower coefficient word length comparing with the conventional cascade structure.

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Design of Optimal Digital IIR Filters using the Genetic Algorithm

  • Jang, Jung-Doo;Kang, Seong G.
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.2 no.2
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    • pp.115-121
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    • 2002
  • This paper presents an evolutionary design of digital IIR filters using the genetic algorithm (GA) with modified genetic operators and real-valued encoding. Conventional digital IIR filter design methods involve algebraic transformations of the transfer function of an analog low-pass filter (LPF) that satisfies prescribed filter specifications. Other types of frequency-selective digital fillers as high-pass (HPF), band-pass (BPF), and band-stop (BSF) filters are obtained by appropriate transformations of a prototype low-pass filter. In the GA-based digital IIR filter design scheme, filter coefficients are represented as a set of real-valued genes in a chromosome. Each chromosome represents the structure and weights of an individual filter. GA directly finds the coefficients of the desired filter transfer function through genetic search fur given filter specifications of minimum filter order. Crossover and mutation operators are selected to ensure the stability of resulting IIR filters. Other types of filters can be found independently from the filter specifications, not from algebraic transformations.

Desing and Analysis of Weather/Wave Observation Network for the Coastal Zone (연안해역의 기상${\cdot}$파랑관측망 설계 및 해석기술의 구축 - 해양파랑관측자료의 해석방법 -)

  • Ryu Cheong-Ro;KIM Hee-Joon;SHON Byung-Kyu
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.30 no.1
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    • pp.16-30
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    • 1997
  • Application of digital filter to the wave analysis is studied using the observed data by wave gauge. Sea wave data obtained from wave gauge always include long wave frequency components. In order to estimate the sea wave parameters, we must re-analyzed wave data by using a digital filter and the concept of mean sea level correction method. By the wave by wave analysis and spectral methods, sea wave parameters on the basis of wave data obtained by the conventional method and digital filter are compared. The best-fitted design filter determined by the necessary conditions of frequency responses, can be obtained by calculating various transfer functions. Thus, to get the best the digital filter design, both Butterworth filter and Savitzky-Golay filter of digital filter are used in the frequency and time domain, respectively. Three cases of observation wave data are calculated by applying digital filter. The components of different frequency bands in the surf zone are coexisted in three cases. The wave data for wind wave components is computed using the digital filter the surf zone and off-surf zone, and based on the filtered data, wave parameters are calculated by the spectral analysis and wave by wave analysis methods, respectively. As a results, when sea wave data observed by wave gauge are analyzed, the Savitzky-Golay method is recommended which can well appear cut-off frequency by experimental choosing filter length in the time domain. The better mean sea level correction method is the Butterworth filter in the frequency domain.

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Study on Design and Implementation of the Low Pass Digital Filter for Biological Signals by a Microprocessor (마이크로프로세서에 의한 생체신호용 저역 디지털 필터의 설계 및 구현에 관한 연구)

  • Lee, Young-Wook
    • The Journal of Information Technology
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    • v.9 no.1
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    • pp.33-39
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    • 2006
  • This study is for the contents of development to the hardware system and software driving algorithm to implement the frequency band of about 7KHz los pass digital filter which has the cut-off frequency of 392Hz by interfacing of a microprocessor with its peripheral analog-to-digital converter chip and digital-to-analog converter chip. The simplicity of digital filter design without difficulty and the implementation of programmed digital filter can be realized by providing the interfacing method to implement the law pass digital filter for the biological signals and the realization method of computer algorithm by a microprocessor.

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A Study on the Design of the Digital Filter Bank Using the Wave Digital Filters (웨이브 디지탈 필터를 이용한 디지탈 필터뱅크의 설계에 관한 연구)

  • 임덕규;한인철;이재석;이종각
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.13 no.2
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    • pp.107-119
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    • 1988
  • An 8-channel digital filter bank with wave digital filters(WDF) is studied. Wave digital filtwr is automatically a directional filter. Using these properties, a new method for organizing the 8-channel digital filter bank is proposed. This will lead to enormous savings in memories for the digital signal processign chip.

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Investigation of Digital Filter Design using Improved Simulated-Annealing Technique (개선된 시뮬레이티드어닐링 기법에 의한 디지탈필터 설계의 고찰)

  • Song, Nag-Un;Yun, Bok, Sik
    • The Transactions of the Korea Information Processing Society
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    • v.2 no.1
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    • pp.106-118
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    • 1995
  • In this work, the optimized design methodology in high-level synthesis related with scheduling and hardware allocation is developed by simulated annealing technique effectively modified . Applying this method to digital filter design, the optimized tradeoff problem of speed and hardware costs in pipelined digital filter case and array digital filter case are investigated. While, it is confirmed that the suggested method gives the improved cost function value faster and can be used in complicated digital filter design.

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Digital Filter Design using the Symbol Pulse Invariant Transformation

  • ;Rokuya Ishii
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.1
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    • pp.1-9
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    • 1994
  • In general, when IIR digital filter are designed from analog filters, the bilinera transformation and the impluse invariant tramsformation are commonly used. It is known, however, that high frequency response of digital filters designed by these transformations can not be well approximated to the sampled analog signals. In this paper, the symbol pulse invariant transformation is analyzed theoretically so that the symbol pulse invariant transformation which was originally application to a rectangular pulse is newly applied to double rate pulse signals and generic shape pulse signals. Also, the relation of spectra between a transfer function of digital filter and one of analog filter is considered. Further, we apply to design the digital high pass filters using the symbol pulse invariant transformation method.

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A Study on Digital Filter Design based on High-order Window Function (고차 창함수 기반의 디지털필터 설계에 관한 연구)

  • Bae, Sang-Bum;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • pp.973-976
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    • 2009
  • Digital signal processing technique use to variety fields including communication. For these signal processing, FIR digital filter is representative. And for FIR digital filter designing, the window function is used to reduce the Gibbs phenomenon which occurs in the coefficient cutting process of the ideal filter. Therefore, in this paper to improve performance of digital filter, a high-order window function was applied. In this simulation, we compared a peak side-lobe and a transient characteristics with the existing window function.

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Design of Two-dimensional Digital Filter by Research and Educational CAD Tools (연구교육용 CAD 툴에 의한 이차원 디지탈필터의 설계)

  • Song, Nak-Un;Kim, Jong-Jun
    • The Transactions of the Korea Information Processing Society
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    • v.3 no.5
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    • pp.1187-1197
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    • 1996
  • In this work, two-dimensional FIR digital filter is designed and simulated using research and educational CAD tools. The two-dimensional digital filter consists mainly of one-dimensional digital filter and line memory. To speed up one-dimensional digital filter, multiplications are carried out on the basis of hardwired-shifting methods by the digital filter coefficients represented in CSD formats, while carry-save adder and Manchester adder are used in addition. It is found that the designed digital filter operates up to 30 Mhz in VHDL simulation and operates normally in IRSIM simulation for the layout made by Berkeley CAD tools.

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