• Title/Summary/Keyword: 디지털신호 처리기

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A Channel estimation for multipath channel and performance of Viterbi equalizer of high speed wireless digital communication (고속 디지털무선통신에 있어서 멀티 패스 채널 추정과 비터비 등화기 의 동작특성)

  • 박종령;박남천;주창복
    • Journal of the Institute of Convergence Signal Processing
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    • v.3 no.2
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    • pp.53-57
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    • 2002
  • Recently, digital communication system becomes high speed, as communication demand dose not only increases sharply, but an image, voice various kinds data also comes multimedia. In transmitting data at a high speed, the main problem is fading by multipath. A linear or nonlinear distortion arise In multipath channel fading from ISI(Intersymbol Interference). For restoring this distorted signal, A lot of equalizer and adaptive algorithm is introduced. This paper compares and analysises, for improving communication quality in channel which is long delay spread, performance of decision feedback equalizer by RLS algorithm, a channel estimation by RLS-MLSE and viterbi equalizer Particularly, there Is exactly channel estimation of impluse response and excellent property of equalization about channel, which delay spread is long impluse response comparatively and is property of non-minimun phase.

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Design and Implementation of Fuzzy PID Controller (Fuzzy PID 제어기 설계 및 구현)

  • Shin Wee-Jae
    • Journal of the Institute of Convergence Signal Processing
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    • v.6 no.2
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    • pp.89-94
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    • 2005
  • In this paper, we propose a fuzzy PID controller of new method. There are two problems in absolute digital PID controller. First, much calculation time need for obtain the sum of data at each period. Second, this is problem need much memory because to storage every data at the before period. We use the speed type PID digital controller to improvement such problems. In the propose controller doesn't use without adjustment the crisp output error and we doesn't use nile tables in the fuzzy inference process at the forward stage fuzzifier. We inference output member ship function by using the relation and range of two variable of PID gain parameters. We can obtained desired results through the simulation and a experiment of the hydraulic servo motor control system.

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Study on Implementation of a Digital Frequency Discriminator using 4 channel Delay line (4채널 지연선로를 이용한 디지털 주파수 판별기 구현에 관한 연구)

  • Kook, Chan-Ho;Kwon, Ik-Jin
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2010.05a
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    • pp.512-515
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    • 2010
  • SIGINT(SIGnal INTelligence) includes several parameters intercepted by measurement and analysis of the RF(Radio frequency) signal from free space. One of the important parameters is frequency information. Expecially, in order to perform instantaneous frequency measurement of Radar and Missile seeker's RF signals, we use dedicated RF modules as a DFD(Digital Frequency Discriminator) to provide frequency information by measurement of the relative phase difference between signals via intended RF delay lines. It must measure and provide realtime based frequency information on short pulsed RF signal up to 100 nSec or less. This document proposes Ultra wideband DFD consisted of a RF input section of Wideband 4 channel RF delay line and correlator, a digital processing section to measure and provide frequency information from I/Q signal, and a frequency calibration section. Also, it will show design suitability based on test results measured under test condition of very short input pulse signals.

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Digital Phase-Locked Loop(DPLL) Technique for UPS (무정전 전원장치용 디지털 위상동기화 기법)

  • 김제홍;최재호
    • The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.11 no.3
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    • pp.106-113
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    • 1997
  • In uninterruptible power supply(UPS), a high speed phase control is usually required to compensate transients in the output voltage at the instant of transfer from the ac line to the inverter when the ac line fails or backs to the ac line in case of the inverter fails. To overcome this problem, this paper pre¬sents the closed digital phase-locked loop(DPLL) techniques designed by full software with TMS320C31 digital signal processor and describes the functional operation of the proposed DPLL. Fi¬nally, the performance of the proposed DPLL is shown and discussed through simulation and experiment.

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Measurement of a Diagnostic Coverage for a Digital Signal Processor Board Using an FMEDA (FMEDA를 활용한 디지털 신호처리기 보드의 진단 유효범위의 측정)

  • Keum, Jong-Yong;Suh, Yong-Suk;Lee, Jun-Koo;Park, Je-Yun
    • Journal of Applied Reliability
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    • v.8 no.2
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    • pp.101-111
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    • 2008
  • Good diagnostics improves both the safety and system unavailability of digital safety systems. The measure of a diagnostic capability is called the Coverage Factor. Because the Failure Modes, Effects and Diagnostic Analysis (FMEDA) provides information on the failure rates and failure mode distributions necessary to calculate a diagnostic coverage factor for a component, the FMEDA can be used as a useful tool to calculate it. Through performing FMEDA on a digital signal processor (DSP) board used in a digital safety system, it is shown that some components of the DSP board can be replaced or improved to satisfy the required diagnostic coverage. That is, the FMEDA can serve as a useful verification tool to design a diagnostic capability for the DSP board.

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Development of X-Ray Array Detector Signal Processing System (X-Ray 어레이 검출 모듈 신호처리 시스템 개발)

  • Lim, Ik-Chan;Park, Jong-Won;Kim, Young-Kil;Sung, So-Young
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.23 no.10
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    • pp.1298-1304
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    • 2019
  • Since the 9·11 terror attack in 2001, the Maritime Logistics Security System has been strengthened and required X-ray image for every imported cargos from manufacturing countries to United States. For scanning cargos, the container inspection systems use high energy X-rays for examination of contents of a container to check the nuclear, explosive, dangerous and illegal materials. Nowadays, the X-ray cargo scanners are established and used by global technologies for inspection of suspected cargos in the customs agency but these technologies have not been localized and developed sufficiently. In this paper, we propose the X-ray array detector system which is a core component of the container scanning system. For implementation of X-ray array detector, the analog and digital signal processing units are fabricated with integrated hardware, FPGA logics and GUI software for real-time X-ray images. The implemented system is superior in terms of resolution and power consumption compared to the existing products currently used in ports.

The Implementation of Image Transmission System Using Turbo Code (디지털 영상전송용 터보코드 시스템 구현)

  • Lee, Sung-Woo;Baek, Seung-Jae;Park, Jin-Soo
    • Proceedings of the Korea Information Processing Society Conference
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    • 2003.05b
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    • pp.1477-1480
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    • 2003
  • 본 논문에서는 실시간 데이터 및 보안데이터, 영상데이터 통을 전송할 때 잡음으로 인해 발생되는 데이터 오류를 효과적으로 복원하기 위해 오류 정정 능력이 뛰어난 터보코드를 적응하여 신뢰성 있는 영상전송 시스템을 실현하였다. 영상처리 시스템에서는 CCTV, 비디오 카메라 등에서 나오는 NTSC(National Television System Committee) 영상 신호를 비디오 디코더를 통해 A/D 변환하여 출력하였다. 변환된 디지털 영상정보는 두 개의 영상필드로 출력되며 그중 하나의 필드가 선택되는 알고리즘을 EPLD(Erasable Programmable Logic Device) 로직회로로 구성하여 디지털 영상 데이터를 절반으로 줄이는 시스템을 구현하였다. 터보코드의 부호기, 복호기 시스템에서는 실수연산이 가능한 DSP(Digital Signal Processor)를 사용하여 터보코드를 구현하였으며, 터보코드의 성능을 좌우하는 인터리버부분은 블록 인터리버를 적용하여 설계하였다.

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