• 대한전자공학회논문지
• /
• 제24권1호
• /
• pp.123-132
• /
• 1987

In this paper, we studied on the design of elliptic digital filters using the bilinear z transformation method, and proposed a design procedure satisfying prescribed specifications. The magnitude characteristics of digital filters are compared with its of analog filiters by computer simulation. Finaly we considered the quantization effects of digital filters. In cascader realization of fixed-point digital filters under dynamic range constraints, the outpout noise for IIR digital filters depends on the pole-zero pairing and ordering of the second order sections. Therfore an optmization procedure to finding a good ordering and pairing is very desirable. Thus, we proposed a sub-optimization procedure for finding "near optimal" solution.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
• /
• pp.817-822
• /
• 1992

Distortion analysis of digital filters for the ECG signal processing is presented. Several band pass and band reject filters are designed for the analysis. Computer simulations are performed to compare the distortions of the Butterworth type filters and linear phase optimal fitters. The designed filters are applied to power line interference cancelling in ECG signals.

• Journal of Electrical Engineering and Technology
• /
• 제4권3호
• /
• pp.423-428
• /
• 2009

In FIR (Finite Impulse Response) filter applications, Nth-band FIR digital filters are known to be important due to their reduced computational requirements. The conventional methods for designing FIR filters use iterative approaches such as the well-known Parks-McClellan algorithm. The Parks-McClellan algorithm is also used to design Nth-band FIR digital filters after Mintzer's research. However, a disadvantage of the Parks-McClellan algorithm is that it needs a large amount of design time. This paper describes a direct design method for Nth-band FIR Filters using Chebyshev polynomials, which provides a reduced design time over indirect methods such as the Parks-McClellan algorithm. The response of the resulting filter is equi-ripple in passband. Our proposed method produces a passband response that is equi-ripple to within a minuscule error, comparable to that of Mintzer's design method which uses the Parks-McClellan algorithm.

• 한국통신학회논문지
• /
• 제11권5호
• /
• pp.315-322
• /
• 1986

本 論文은 　圓函數를 利用한 IIR digital 필터 設計에 關하여 硏究한 것이다. Digital 　圓函數는 analog 　圓函數로부터 Bilinear z 變換에 依하여 求하였다. Bilinear z 變換된 函數로 digital필터를 設計하면 aliasing 現象은 避할 수 있으나 周波數歪曲이 發生한다. Analog函數를 digital函數로 變換하면 이러한 影響으로 遮斷周波數 領域이 不一致하므로 이것을 避하기 爲하여 prewarping法을 利用하였다. 마지막으로, 컴퓨터 simulation에 依하여 analog 크기 特性과 digital 크기 特性을 比較한 結果, prewarping을 한 digital 크기特性이 analog 크기 特性에 比하여 改善되었음을 確認할 수 있었다.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• 제2권2호
• /
• pp.115-121
• /
• 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.

• 대한전기학회논문지:시스템및제어부문D
• /
• 제54권10호
• /
• pp.630-638
• /
• 2005

In FIR (Finite Impulse Response) filter applications, Nth-band F]U digital filters are known to be important due to their reduced computational requirements. The conventional methods for designing F]U filters use iterative approaches such as the well-known Parks-Mcclellan algorithm. The Parks-Mcclellan algorithm is also used to design Nth-band FIR digital filters. But a disadvantage of the Parks-Mcclellan algorithm is that it needs a good amount of design time. This paper describes a direct design method for Nth-band FIR Filters using Chebyshev polynomials, which provides a reduced design time over indirect methods such as the Parks-Mcclellan algorithm. The response of the resulting filter is equiripple in passband. Our proposed method produces a passband response that is equripple to within a minuscule error, comparable to that of the Parks-Mcclellan algorithm.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2004년도 ICEIC The International Conference on Electronics Informations and Communications
• /
• pp.199-203
• /
• 2004

In this paper, we only describe the digital block of two-channel 18-bit analog-to-digital (A/D) converter employing sigma-delta method and xl28 decimation. The device contains two fourth comb filters with 1-bit input from sigma­delta modulator. each followed by a digital half band FIR(Finite Impulse Response) filters. The external analog sigma-delta modulators are sampled at 6.144MHz and the digital words are output at 48kHz. The fourth-order comb filter has designed 3 types of ways for optimal power consumption and signal-to-noise ratio. The following 3 digital filters are designed with 12tap, 22tap and 116tap to meet the specification. These filters eliminate images of the base band audio signal that exist at multiples of the input sample rate. We also designed these filters with 8bit and 16bit filter coefficient to analysis signal-to-noise ratio and hardware complexity. It also included digital output interface block for I2S serial data protocol, test circuit and internal input vector generator. It is fabricated with 0.35um HYNIX standard CMOS cell library with 3.3V supply voltage and the chip size is 2000um by 2000um. The function and the performance have been verified using Verilog XL logic simulator and Matlab tool.

• 한국해양학회지
• /
• 제19권2호
• /
• pp.133-140
• /
• 1984

디지탈필터(digital filter) 중에서 특히 순환필터(recursive filter)와 Hamming window를 사용한 종합필터(convolution filter)의 해양학적 응용에 대해 논하였다. 종합필터는 이해하기 쉬우며 설계가 간단하지만, 자료수가 많은 경우에는 비경제 적이다. 순환필터는 설계가 다소 복잡하지만, 필터의 특성이 좋으며 경제적이다. 여름철(1973∼1979) 부산 해안선에 평행한 바람과 감포의 표면해수온도간에 저주파(주기 5일 이상) 성분은 상관관계가 뚜렷하나, 고주파 성분은 상관관계가 거의 없음을 디지탈필터를 사용함으로써 밝혀 내었다.

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

• Journal of Advanced Marine Engineering and Technology
• /
• 제31권7호
• /
• pp.863-871
• /
• 2007

This paper proposes a methodology to estimate the system coefficients for the infinite impulse response(IIR) digital filters using real code GA. In the traditional real coded GA, it adapts the general genetic operations, whereas in this paper the proposed real coded GA applies improved genetic operations in order to search the optimal solution in given problems. Each of unknown IIR digital coefficients collected as forms of a chromosome. Two illustrative examples including the band pass and band stop IIR digital filters are demonstrated to verify the proposed method.