• International Journal of Fuzzy Logic and Intelligent Systems
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• 제2권2호
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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.

• 한국통신학회:학술대회논문집
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• 한국통신학회 1987년도 춘계학술발표회 논문집
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• pp.219-222
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• 1987

A Semi-cusion VLSI Digital Filter Design for TDM/FDM tran-smultiplexer is decribed. Using the polyphase network approach a filter bank composed of only all-pasdigital filter sections was designed. The use of all-pass filters as basic building blocks is shown to provide a Transmultiplexer structure that has low computational requirements low quanization noise and hign modularity. A design of 1st order 2nd All pass filter is done using COMS 2um double metal.

• 대한전자공학회논문지
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• 제25권2호
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• pp.227-232
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• 1988

A semicustom VLSI design fo digital filters used in TDM/FDM transmultiplexer is described. A filter bank composed of only all-pass digital filter sections are implemented with the polyphase network. The use of all-pass filters as basic building blocks is shown to provide a trans-multiplexer structure that has low computational requirements, low quantization noise, and high modularity. The silicon compiler system is used to reduce the design time and to increase the credibility of designed filters. As a prototype, 1st and 2nd order all pass filter are designed, using CMOS N-well double metal technology. The chip sizes of first order filter and the second order filter are 2652 x 533\ulcorner\ulcorner 5334x4300\ulcorner\ulcorner respectively.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
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• pp.850-853
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• 1987

A VLSI digital filter design using a semi-custom method is described. The digital filters composed of TDM/FDM Transmultiplexer are designed. Using the polyphase network approach a filter bank composed of only all-pass digital filter sections was designed. The use of all-pass filters as basic building blocks is shown to provide a transmultiplexer structure that has low computational requirements, low quantization noise, and high modularity. The silicon compiler systems is used to reduce the design time and increase the credibility of designed filters. A design of 1st order and 2nd order all pass filters is done using CMOS 2um N-well double metal cell.

• 정보학연구
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• 제9권1호
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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.

• 산업기술연구
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• 제14권
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• pp.3-17
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• 1994

This paper develops a design technique for approximating nonseparable frequency characteristics by sums and products of separable transfer functions. Therefore nonseparable frequency characteristics includes the four-quadrant symmetry filters. The desired filter with half plan symmetry is obtained by shifting a low pass characteristic in the frequency domain, and by combining these shifted characteristics. Also the paper develops the technique for designing recursive and nonrecursive two dimensional digital filters by the application of a complex transformation to one dimensional low pass filter.

• 전기전자학회논문지
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• 제3권1호
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• pp.11-21
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• 1999

본 논문은 기존의 오디오 DAC 칩 외부의 아날로그 저역통과 필터를 하나의 칩에 집적하기 위하여 디지털 보간 필터의 구조를 FIR와 IIR 필터를 혼합한 구조를 제시하였다. 제시된 디지털 보간 필터를 이용한 ${\Delta}{\Sigma}$ 변조기 출력은 통과대역 내 (>$0.41{\times}fs$) 진폭은 ${\pm}0.001dB,\;0.41{\times}fs$에서 감쇠는 -0.0025[dB], 저지대역 이상(>$0.59{\times}fs$)에서 감쇠는 -75dB였고, 통과대역 내에서 군지연이 30.07/fs[s]이고, 군지연 오차가 0.1672%였다. 또한 저지대역 65[kHz]에서 감쇠가 약 -20[dB] 향상되어 이로 인해 기존의 디지털 보간 필터 구조에 비해 아날로그 저역통과 필터의 RC 적을 감소시킬 수 있음을 알 수 있었다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(1)
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• pp.93-96
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• 2000

This paper has been proposed an audio DAC structure composed of FIRs and IIR filters as digital interpolation filter to integrate the off-chip analog low-pass filter on-a-chip. The passband ripple(< 0.41${\times}$fs), passband attenuation(at 0.41${\times}$fs) and stopband attenuation(> 0.59${\times}$fs) of the Δ$\Sigma$ modulator output using the proposed digital interpolation filter had ${\pm}$ 0.001 ［㏈］, -0.0025［㏈］ and -75［㏈］, respectively. Also the inband group delay was 30.07/fs［s］ and the error of group delay was 0.1672%. Also, the attenuation of stopband has been increased -20［㏈］ approximately at 65［㎑］, out-of-band. Therefore the RC products of analog low-pass filter on chip have been decreased compared with the conventional digital interpolation filter structure.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 하계종합학술대회논문집
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• pp.847-850
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• 1998

One of the most difficult problem of designing VLSI is a mixed-circuit design, that is to design circuit containing both analog parts and digital parts. Digital to analog converter and analog to digital converter is a typical case. Especially it can be a serious problem when mixed circuit are put into a large digital circuit like microcontroller. However nowadays this problem is settled by separating analog circuit parts outside the IC. This technique is based on converting a digital signal into a pulse sequence. Then an analog signal is obtained by averaging this pulse sequence at the external low-pass filter. An anlog to digital converter is designed using a stochastic logic instead of a traditional PWM (pulse-width modulation) signal and ins implemente dusing FPGa. Stochastic pulse sequence can be made as a simple circuits and moreover can be mathematically processed by simple circuits -AND gates. The spectral property of stochastic pulse sequence method is better than that of PWM method. So it make easy to design a external low-pass filter. This technique has important advantages, especially the reduction of the ADC cost.

• 한국멀티미디어학회논문지
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• 제9권4호
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• pp.443-450
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• 2006

디지털 영상 통신 시스템에서 YUV 4:4:4 영상을 저역 필터 통과 후 샘플링한 YUV 4:2:0 또는 YUV 4:2:2 영상이 이용되고 이 영상은 보간 필터 수행 후 원래 크기로 회복된다. 저역 필터와 보간 필터의 사용은 영상 통신 시스템에서 일반적이다. 따라서 영상의 품질을 높이기 위해서 효율적인 저역 필터와 보간 필터는 여전히 필요하다. 본 본문에서는 새롭고 효율적인 저역 필터와 보간 필터를 제안하고 이 필터들을 구축하는 방법론을 제시한다. MPEG-2와 같은 기존 시스템에서 사용되는 저역 필터와 보간 필터는 개별적으로 개발되었다. 본 논문에서는 웨이블릿 변환 기반으로 저역 필터와 보간 필터의 상호 조율하여 필터들을 개발한다. 잘 알려진 영상들에 대한 실험 결과는 MPEG-2에서 사용되는 필터와 비교하여 제안된 필터가 보간 필터의 길이도 더 짧을 뿐만 아니라 PSNR 면에서 더 우수한 것을 보여준다.