• Title/Summary/Keyword: Modem.

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A Study on the Development of Tele-Consulting System of Radiology using Asymetric Satellite Data Communication System (비대칭 위성 데이터 통신 시스템을 이용한 원격 진단 방사선 컨설팅 시스템 개발에 관한 연구)

  • Hwang, S.C.;Kim, Y.M.;Kim, H.J.;Lee, M.H.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.11
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    • pp.180-183
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    • 1997
  • In this paper, we present the Tele-consulting system of radiology, which uses the communication network as asymetric satellite data communication system. The asymetric satellite data communication system uses receive-only satellite links or data delivery and PSTN(Public Switched Telephone Network) modem or N-ISDN(Integrate Services Digital Network) for communication. The satellite communication linking shows the very high-speed performance than 28.8kbps modem linking. The satellite linking is 5 - 10 times aster than the modem linking. Consequently, we get the conclusion that our system is suitable or tele-radiology and telemedicine.

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A Design of Multi-Channel Biotelemetry for ECG Encoding and Transmission Over the Public Telephone Line (공중 전화회선용 다중 채널 ECG데이터 원격 측정시스템 설계)

  • Gye, Sin-Ung;Jang, Won-Seok;Hong, Seung-Hong
    • Journal of Biomedical Engineering Research
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    • v.7 no.1
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    • pp.21-34
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    • 1986
  • In this paper, we described the ECG telemetry system via the Public Telephone Line. The system consist of a signal acquisition and measurement section, a signal processing section, and a signal transmission section. It used 8 bits microprocessor. The transmission section is composed of 3 ch. analog modulators and 1 ct. digital modem. Especially, using the digital modem, signal is transmitted with about 50n data reduction ratio by the TP (Turning Point) algorithm. The acoustic coupler or inductive coil for linking the public telephone line are used. The speed of the digital modem is 300 baud rate. The MCBS (Multi Channel Biotelemetry System) is tested and evaluated through the experiment.

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Design and Implementation of OCQPSK/HPSK Modem using Digital Signal Processors for Software Defined Radio Applications

  • Cho, Pyung-Dong;Kang, Byeong-Gwon
    • Proceedings of the IEEK Conference
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    • 2002.07c
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    • pp.1428-1431
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    • 2002
  • It is general opinion that the future mobile multimedia networks will use different standards and a prospective solution to this problem will be software defined radio (SDR) techniques. SDR provides the flexibility to support multiple air interfaces and signal processing functions at the same time. Especially, digital signal processors and FPGAs are widely used for implementation of these adaptive and flexible functions of a baseband modem for SDR applications. Also, it is known that the modulation schemes of OCQPSK (Orthogonal Complex QPSK) and HPSK (Hybrid PSK) are used for IMT-2000 services of cdma2000 and WCDMA, respectively. Thus, in this paper, we design and implement an OCQPSK / HPSK modem using a DSP chip of Texas Instrument's TMS320C6701. One modulation scheme is operated by adaptive selection between the two schemes and 5 physical traffic channels differentiated by orthogonal codes are implemented in one DSP chip and each channel has 1Mbps data rates and 8Mcps chip rates.

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An Implementation of DOCSIS 3.1 Cable Modem and Performance Evaluation (DOCSIS 3.1 케이블모뎀 구현 및 데이터 전송 성능 평가)

  • Kim, Kyung-dal;Lee, Sang-keun;Kim, Jae-hak;Cho, Sang-hoon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2018.10a
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    • pp.574-576
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    • 2018
  • We implemented DOCSIS 3.1 Data Cable Modem and evaluated the feasibility of high speed data service utilizing high modulation order of 1024 QAM or greater through the small field trial.

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Signal Measurement Algorithm for 3GPP WCDMA Measurement Equipment (3GPP WCDMA모뎀 계측장비를 위한 신호계측 알고리듬)

  • Hong, Dae-Ki
    • Journal of the Semiconductor & Display Technology
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    • v.10 no.1
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    • pp.7-15
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    • 2011
  • In this paper, we implement measurement functionality for the 3GPP (Third Generation Partnership Project) WCDMA (Wideband Code Division Multiple Access) modem. Generally speaking, the receiving algorithms in normal modems cannot be used directly to the measurement system due to the lack of the measurement accuracy. In this paper, we propose the new measurement algorithm for precise 3GPP WCDMA signal measurements. In the measurement algorithm, 4-stage parameters estimation scheme is used. To improve the measurement accuracy, we increase the number of the received signal samples by interpolation. The proposed 3GPP WCDMA signal measurement algorithm can be used for verifying and implementing SoC/FPGA modem measurement systems.

Comparison between S-CDMA and TDMA or Cable Modem Upstream Channel

  • Kim, Ki-Yun;Lee, Hyoung-Geun;Kim, pan-Soo;Park, Hyung-Jin;Cho, Bung-Hak
    • Proceedings of the IEEK Conference
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    • 2000.07b
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    • pp.760-764
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    • 2000
  • In this paper, we compare the major issues associated with TDMA and S-CDMA, which is planned to be adopted as a new cable modem technique for upstream channel. In particular, we mainly deal with the following 3 topics: MAC protocol, modem structure and BER performance comparison between TDMA and S-CDMA.

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The Study of Wireless Modem Receiver Design for Mobitex (Mobitex용 무선모뎀 수신부 설계에 관한 연구)

  • 오승철;송창영
    • Journal of the Korea Computer Industry Society
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    • v.3 no.1
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    • pp.67-76
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    • 2002
  • This thesis aims at the study of the receiving part of wireless modem for Mobitex, which are designed for two way massage services by using the network of wireless packet. This receiving part has the features of GMSK demodulation by using Gaussian filter, which has the co-amplitude in a better condition and narrowness bandwidth and high performance in BER, compared with existing MSK modulation. In case of BT=0.3, we designed this receiving part to reduce RF output power spectrum at received data of symbol demodulation and avoid inter symbol interference(ISI) so that we can apply this part to Mobitex network which are currently in service for wireless modem in domestic.

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Low Power SoC Modem Design for High-Speed Wireless Communications (초고속 무선 통신을 위한 저전력 모뎀 SoC 설계)

  • Kim, Yong-Sung;Lim, Yong-Seok;Hong, Dae-Ki
    • Journal of the Semiconductor & Display Technology
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    • v.9 no.2
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    • pp.7-10
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    • 2010
  • In this paper, we design a modem SoC (System on Chip) for low power consumption and high speed wireless communications. Among various schemes of high speed communications, an MB-OFDM (Multi Band-Orthogonal Frequency Division Multiplexing) UWB (Ultra-Wide-Band) chip is designed. The MB-OFDM uses wide-band frequency to provide high speed data rate. Additionally, the system imposes no interference to other services. The 90nm CMOS (Complementary Metal-Oxide Semiconductor) technology is used for the SoC design. Especially, power management mode is implemented to reduce the power consumption.

A Study on the African Image Expressed in 2005 S/S Collections (2005 S/S 컬렉션에 나타난 아프리카 이미지 연구)

  • Lee, Keum-Hee;Kim, Wan-Joo;Kim, So-Ra
    • Journal of the Korean Society of Clothing and Textiles
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    • v.31 no.6 s.165
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    • pp.911-922
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    • 2007
  • In this study, for the purpose of correct viewing on the image of Africa and understanding of modem fashion, African image and art, the general characteristics of African costume, the background of fashion subjecting African image, and the trend according to ages were examined based on theoretical background. Then the researcher drew African image by analyzing the works in four 2005 S/S major fashion collections to designers and design factors. The ten voted designers' and brands' works in 2005 S/S collections had four concepts of African image; 'Wild Erotic', 'Abstract Primitive', 'Natural Elegant' and 'Sporty Romantic'. The viewpoint of modem fashion on African image from the aspect of design, designer and fashion trend can be examined as below. First, African costume, which was religious and ceremonial, appeared to emphasize its esthetic side with decorative details in modem fashion design and designers competed to choose a method to harmonize tradition and modem style and by adopting these from occult to decorative meaning, Second, fashion designers presented city unpolished beauty of modem women to a special style and made african image to be recognized as a code of fashion culture by integrating it with modem people's mind to go back to the past and admiration for the purity of nature. Third, thanks to the instinctive vitality hidden in the primitive life, inspiration for creative design that is found in the esthetic mind of the Indians, foreign taste emphasizing ethnic trend, and admiration to naturalism due to the increase of concern over ecology, 'African image' led the beginning of 21C trend by being settled as a in fashion trend.

A Study on the Digital Design for Voice Modem Using the Multicarrier DS-CDMA in Powerline Channels (전력선 채널에서 멀티캐리어 DS-CDMA를 이용한 전력선 음성모뎀의 디지털부 구현에 관한 연구)

  • 이상준;김민걸;이종성;구시경;박광철;오정현;김기두
    • Proceedings of the IEEK Conference
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    • 2000.06a
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    • pp.77-80
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    • 2000
  • In this paper, we implemented the voice modem using the multicarrier DS-CDMA in powerline channels. Both TMS320C5402 of Texas Instrument and FPGA FLEX 10K EPF10K100ARC240 of ALTERA are used to realize the proposed system. For robustness in the powerline channel, we used multicarrier DS-CDMA modulation, convolutional encoding/Viterbi decoding, and interleaving. Finally, we showed satisfactory performance in the laboratory experiment.

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