• 제목/요약/키워드: Modem.

검색결과 1,809건 처리시간 0.027초

S-DMT 방식 케이블 모뎀을 위한 주파수 동기 알고리즘 설계 (Design of a Frequency Synchronization Algorithm for S-DMT Cable Modem)

  • 조병학
    • 디지털콘텐츠학회 논문지
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    • 제8권3호
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    • pp.385-391
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    • 2007
  • HFC 망 상향채널의 용량을 증대시키기 위한 차세대 케이블 모뎀 기술의 하나인 S-DMT 방식 케이블 모뎀의 주파수 동기 알고리즘 제안하고 성능을 평가하였다. 다수 반송파 전송 시스템의 주파수 동기 알고리즘들에 대한 분석을 통하여, 데이터 프레임의 프리앰블 필드 내에 약속된 반복 패턴의 훈련열을 삽입하여 전송하고, 파일롯 신호를 이용하여 잔류 주파수 오프셋에 따른 위상오차를 보정하는 방법을 제안하고 시뮬레이션을 통해 AWGN 잡음 환경에서의 성능을 평가 하였다. 성능 평가 결과, 파일롯 신호의 수와 크기에 따라 성능 차이를 보이나, 제안한 주파수 동기 알고리즘이 신속한 동기를 필요로 하는 S-DMT 방식 상향채널 케이블 모뎀에 적합하고 양호한 성능을 보임을 확인하였다.

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SDH 무선 시스템의 64 QAM RF MODEM을 위한 DFE 구현 (Implementation of Decision Feedback Equalizer for 64 QAM RF MODEM in SDH Radio Systems)

  • 이대령;방효창;장태화;안준배;조성준;김원후
    • 한국통신학회논문지
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    • 제19권5호
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    • pp.928-938
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    • 1994
  • 본 논문에서는 SDH STM-1 신호인 64 QAM RF MODEM (155Mbps급)에서의 ZF(Zero Forcing) 알고리즘을 사용한 (3.3) 탭 Decision Feedback Equalizer를 설계 및 구현 하였다. 설계에 앞서 이루어진 시뮬레이션 결과로부터 11탭 선형등화기에 비해 (3.3) 탭 DFE가 fading 환경에서 약 5dB 정도 우수한 성능을 나타냈으며, 실현 구현된 등화기의 실험결과 fade depth 가 20dB인 경우에도 정상적인 등화성능을 나타내었다.

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지상 방송용 고선명 텔레비젼을 위한 전 디지탈 모뎀 (An all-digial HDTV modem for terrestrial broadcasting)

  • 한동석;신현수;최양석;송동일
    • 한국통신학회논문지
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    • 제21권7호
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    • pp.1777-1786
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    • 1996
  • This paper describes theories and implementation techniques of a digital high-definition television(HDTV) modem based on 32-QAM for terrestrial broadcasting. We proposed a digital demodulation scheme and a symbol timing recovery structure based on the band edge component maximization(BECM) method. The adaptive equalizer has 256 complex taps to remove the multipath of delays ranging from -2.mu.s~+24.mu.s with a new T/2-spaced blind equalization algorithm. computer simulation results reveal that the proposed algorithm outperforms other conventional blind equalization algorithm a digital HDTV modem with 4.91MHz symobol rate is implemented by utilizing the proposed algorithms. All processings for modem operations such as demodulation, estimation of symbol timing phase error, adaptive equalization, and carrier recovery except IF signal processing and sampling phase control part of the AD converter are done in digital domain. Especially, the carrier recovery loop can track a carrier offset of upto .+-.350KHz.

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Development of Data-Flow Control Algorithm of Wireless Network for Sewage Disposal Facility

  • Jung, Soonho;Shin, Jaekwon;Kang, Jeongjin;Lee, Seungyoun;Lee, Junghoon
    • International journal of advanced smart convergence
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    • 제4권2호
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    • pp.14-19
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    • 2015
  • Recently, water sewage disposal facilities are able to manage real-time data collection and record management through compact broadband modem LAN switching technology. Therefore, it needs more stable and efficient facility management. So, we required practical use of environmental facilities convergence based on broadband integrated modem. In this paper, we proposed short distance wireless communication network of compact broadband modem for sewage disposal facilities. And it received data inside of water treatment facility using the two communication methods (IEEE802.11x and IEEE802.15.4x). Then, our proposed an data-flow control algorithm of wireless network technology will prioritize processing data when emergency happen through collecting data, analysis data and processing. Lastly, we proved usefulness by experiment and simulation analysis.

저속 PLC 모뎀을 위한 대기전력 절감 모듈 개발 (A Development of Module Operating on Standby-power Reduction for Low-speedy PLC Modem)

  • 김기현;김지홍;김남균;김상철;서길수;김은동
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 하계학술대회 논문집 B
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    • pp.1537-1539
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    • 2004
  • This paper introduces a supplementary module reducing the standby-power of Power Line Communication(PLC) modem, one of the network equipments that take up much of the stand-by power. This supplementary module consists of three parts, such as a compare part, a control part, and a switch part. This supplementary module controls the power going from the power supply element into PLC modem, which brings about the effect of standby-power reduction. It is assured that over $30\%$ standby-power reduction is estimated when we applied this module to a low-speedy PLC control modem.

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특성화된 수중음향통신모뎀을 위한 신호처리 모듈 구현 (Signal Processing Module Development for Specialized Underwater Acoustic Communication Modem)

  • 박영준;김영길
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2010년도 춘계학술대회
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    • pp.258-261
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    • 2010
  • 기존의 수중음향통신모뎀은 상용 제품들을 기반으로 개발되어 수중음향통신모뎀의 기능 및 성능 구현은 가능하지만 개발 시스템을 제품화하기에는 시스템의 크기나 개발 비용 등에서 단일 플랫폼으로의 시스템 구현이 필수적으로 요구되었다. 따라서 본 논문에서는 수중음향통신모뎀의 단일 하드웨어 플랫폼을 구현함에 있어 중요한 역할을 하는 신호처리 모듈을 TigherSHARC DSP 칩을 이용하여 설계 및 구현하고자 한다.

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제어용 PLC 모뎀을 위한 대기전력 절감 모듈 개발 (A Development of Module Operating on Standby-power Reduction for PLC Control Modem)

  • 김기현;김지홍;김남균;김상철;서길수;김은동
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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    • pp.296-299
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    • 2004
  • This paper introduces a supplementary module reducing tile standby-power of Power Line Communication(PLC) modem, one of the network equipments that take up much of tile stand-by power. This supplementary module consists of three parts, such as a compare part, a control part, and a switch part. This supplementary module controls the power going from the power supply element into PLC modem, which brings about the effect of standby-power reduction. It is assured that over 30% standby-power reduction is estimated when we applied this module to a low-speedy PLC control modem.

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현대 패선 디자인에 나타난 고저스 이미지 경향에 관한 연구 (A Study on the Tendency of Gorgeous Image in Modern Fashion Design)

  • 이언영;이인성
    • 대한가정학회지
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    • 제42권10호
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    • pp.115-128
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    • 2004
  • Social structure has diversified, and changed into the form of pluralism since entering the 21st century. Specially, entering in the 21st century modem fashion is expressed to the luxurious feminism which expresses sensual, strong, and decorative elegant based on the womanly beauty. The gorgeous image is a splendid and luxurious image. Also it is the fashion image which is expressed strongly by the decorative detail elements among the design components. Then, it appears often in modem fashion as the pursuit image of modem persons. Therefore, the purpose of this study was not only to analyze the meaning providence and the diagnostic elements about the gorgeous image that appears often in modem fashion, but also to help the various fashion image representations by arranging the presenting principle and the method of fashion image systematically setting in the trend toward modem fashion. The method of this study was a theoretical research of the literature materials concerned with fashion images by the clothes. Also, the questionnaires were completed by selected specialists as investigation subjects who were variously engaged in the fashion-related fields in order to research the gorgeous image. In the above results. the gorgeous image's diagnostic constituent was grasped laying stress on the characteristic of the clothes. Then, the whole concept named Luxury Imagination was chosen, and 4 suits of the gorgeous image were produced by these results In the diversified and personalized modem fashion with he above results the flowing of the gorgeous image is the part able to be expressed exactly in the view of the image pursued by the public.

현대패션에 나타난 낭만주의 양식의 부재와 유사 (Absence and Resemblance of Romantic Style in Modern Fashion)

  • 김정미
    • 복식
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    • 제61권1호
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    • pp.94-108
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    • 2011
  • The goal of this dissertation is to analyze various Romantic styles appearing in modem fashion based upon the 'Difference' theory developed by Michel Foucault. The characteristics that represent 'difference' in change of dress style are absence and resemblance. They are derived from the Foucault's interpretations of 'difference' represented in the paintings by Vel$\acute{a}$zquez and Magritte. The formative characteristics of the Romantic style dress in the 19th century are suppression of body, fixed form, volume, and ornamentation. And the aesthetic values of that are subordination, sensuality, and maternity. The formative characteristics of the Romantic style that have appeared since 1980s is analyzed according to absence and resemblance. The results are as follows: first, absence in fashion means that body is more emphasized than dress represented by omitting part or the entire of dress or using the transparent materials. In modem fashion, absence also frees the body from dress and creates ambiguity of boundaries between body and dress. Another characteristic of the absence is lessening the volume, which means the size of dress remains still big but the weight is lightened. Second, resemblance means the formative similarities between the Romantic style of the $19^{th}$ century's and that of modem fashion created through using modem technology and materials. The characteristics of the resemblance are the fixed form, lessening of volume of the dress and ornamentation. Feminine beauty inherent in the original, such as subordination, sensuality, and maternity, looses its symbolic meaning and what is created is a new combination of images and signifiant that contain no or uncertain meanings. Thus totally new and different Romantic style is created. The Romantic style in modem fashion changed into the appropriate style to the modem society under various conditions such as designer's will, postmodernism, changes of femininity and technology.

CDMA/TDMA 기반 무선 원격계측 시스템용 모뎀의 VLSI 구조 설계 (A VLSI Architecture Design of CDMA/TDMA Modem Chipsets for Wireless Telemetry Systems)

  • 이원재;이성주;이서구;정석호;김재석
    • 대한전자공학회논문지SD
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    • 제41권5호
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    • pp.107-114
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    • 2004
  • 본 논문에서는 CDMA 및 TDMA 기술을 기반으로 하는 무선 원격계측 시스템용 모뎀에 적합한 최적 하드웨어 구조 및 VLSI 설계에 대해서 제시한다. 무선 원격계측 시스템은 계측이 필요한 다수의 지점에 소형 무선계측기(RT: Remote Terminal)를 설치하고, 설치된 무선계측기로부터 계측데이터를 무선으로 수집하기 위해 제안된 시스템이다. 무선 원격계측 시스템은 계측데이터를 전송하기 위한 다수의 RT와 RT로부터 데이터를 수집하는 1개의 CU(Central Unit)로 구성된다. 본 논문에서는 이러한 RT와 CU용 모뎀에 적합한 최적 하드웨어 구조를 제안하였고, 제안된 구조를 Verilog HDL로 설계 및 검증하였다. Verilog HDL로 설계된 모뎀은 Synopsys/sup TM/툴을 이용하여 게이트 수준으로 합성되었고, 합성결과 RT 및 CU용 모뎀은 0.6㎛ 공정에서 각각 약 27K 게이트와 222K 게이트의 하드웨어 복잡도를 가졌다. 제안된 모뎀은 Altera/sup TM/ FPGA로 구현 및 검증되었다.