• Title/Summary/Keyword: High Data-rate Transmission

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Design of MAGLEV Information Transmission System by Radio Inductive Loop (유도무선루프에 의한 자기부상열차 정보전송 시스템의 설계)

  • An, Sang-Gwon;Park, Seok-Ha;Park, Jeong-Su;Kim, Jong-Beom;Kim, Yang-Mo
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.48 no.1
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    • pp.42-47
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    • 1999
  • This paper presents the information transmission between on-board and ground-site in MAGLEV. considering safety and high speed operation and density operation, information transmission between them is necessary. Therefore it is necessary for transmission system to ensure high speed transmission, low error rate, massive information, and reliability of information. To provide above conditions, 1.1km signal line assembly was constructed and Frequency Shift Keying(FSK) modulation and Open System Interconnection(OSI) based high-level data link control(HDLC) protocol are applied. To modulate digital signal for transmission from ground-site to on-board, carrier frequency of 70kHz is used and 90khz is used for transmission from on-board to ground-site. Transmission speed is 2400bps for consideration of train speed, quantity of information, and data error rate. And this paper introduces information monitoring considering user interface and presents the method for an effective data transmission in MAGLEV which is now being tested and intends to provide for an intelligent train operation system in future.

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Improved Binary CDMA Modem Design for High-Speed Wireless Communications (고속데이터 전송을 위한 개선된 Binary CDMA 모뎀 구현)

  • Lee, Jang-Youn;Cho, Jin-Woong;Hong, Dae-Ki
    • Journal of the Semiconductor & Display Technology
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    • v.9 no.2
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    • pp.11-14
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    • 2010
  • In this paper, an improved binary-CDMA (Code Division Multiple Access) system for high speed multimedia data transmission will be presented. The improved binary CDMA technology will be used in municipal wireless network. The new name of the system is the Guardian system using a binary CDMA technology. The Guardian system can provide high data rate, and improve its throughput by minimizing latency from the limitation of resources of system bus during multimedia data transmission. Finally, we analyze the performance of Guardian modem according to the report of wireless data transmission test.

High-rate LDPC Coded OFDM System for Image Transmission over Rayleigh Fading Channel (레일리 페이딩 채널에서 이미지 전송을 위한 고속 LDPC부호를 적용한 OFDM 시스템)

  • Choi, Sang-Min;Moon, Byung-Hyun
    • Proceedings of the KIEE Conference
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    • 2005.05a
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    • pp.233-235
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    • 2005
  • As a class of block codes, LDPC code with any desired code rate and code length is easily constructed. In OFDM system high data transmission is possible, In this paper, we examined the performance of four high-rate(0.75, 0.8, 0.889, 09412) LDPC coded OFDM in image transmission over Rayleigh fading channel. The high-rate of 0.9412 LDPC coded OFDM system obtained about 12dB gain over the OFDM at BER of $10^{-3}$ over Rayleigh fading channel. Also, the PSNR of code rate 0.9412 LDPC coded OFDM system at SNR=10dB is given by 18.8047dB where uncoded OFDM system gives 9.7303 dB.

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Implementation of Adaptive Transmission Middleware for Video Streaming (비디오 스트리밍을 위한 적응적 전송 미들웨어의 구현)

  • 김영주
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.3
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    • pp.637-644
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    • 2004
  • This paper proposed and implemented the adaptive transmission middleware for video streaming, which is able to support the adaptive transmission of video data to the fluctuating changes of network environment in the packet-based network and the properties of transmitted video data. The adaptive transmission middleware is made up SR-RTP-based transfer module and TFRC(TCP Friendly Rate Control)-based transfer-rate control module. The SR-RTP-based transfer module supports RTP-based real-time transfer of video data and packet retransmission scheme retransmitting the high-priority packets selectively in the damaged video data to reduce the error induced by the packet loss. Sharing the transmission bandwidth of network with the TCP-based data transfer, the TFRC-based transfer-rate control module controls the transfer rate of video data according to the most allowable transmission bandwidth in the network, so that the transfer rate is controlled adaptively to the fluctuating changes of transmission bandwidth. This paper, for the experiment, applied the adaptive transmission middleware to video streaming in the external Internet environment, and analyzed the effective frame transfer rate and the degree of the streaming jitter to evaluate the performance of packet-loss recovery and adaptive transfer rate control. In the external Internet environment where the packet-loss rate is high a bit, the relatively high streaming performance was showed compared with the case that didn't apply the adaptive transmission middleware.

Phase Noise Spectrum of LNB for PSK Multi-mode satellite transmission signal (PSK 고차모드 위성전송을 위한 저잡음 증폭 주파수 변환기의 위상 잡음 해석)

  • Kim, Young-Wan
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.7
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    • pp.1180-1186
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    • 2008
  • The LNB phase noise of user terminal for high data rate satellite transmission was analyzed in this paper. The phase noise severely affects the service performance in low data rate transmission as well as multi-mode signal for high data rate. As the satellite link frequency is increased, the effects of phase noise for multi-mode signal is increased. The phase noise of LNB, which is operated in high frequency band, is about equal to the transmission system phase noise and have an major effects on service performance degradation. The available transmission mode was analyzed in presence of phase noise of LNB and analysis method for LNB phase noise spectrum distribution was proposed in multi-mode signal.

Performance Evaluation focused on Burst of Smoothing Algorithms (스무딩 알고리즘들의 버스트 성능 평가)

  • Lee, Myoun-Jae
    • Journal of Digital Contents Society
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    • v.13 no.1
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    • pp.111-118
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    • 2012
  • The burst is to require abruptly high transmission rate in case of transmitting pre-stored variable bit rate video data, and it causes to be inefficient use of network resource, resource reservation. To avoid these problems, smoothing is transmission plan where variable rate video data is converted to a constant bit rate stream. These smoothing algorithms include CBA, MCBA, MVBA and others. To evaluate amount of burst reduction in the existing CBA, MCBA, MVBA algorithm, this paper compares the burst-related-factors of transmission plan in smoothing algorithms with original video sources which were stored Variable Bit Rate. There are maximum frame bytes, maximum GOP bytes, transmission rate variability per frame, transmission rate variability per GOP in burst-related evaluation factors. Experimental result shows burst-related factors of smoothing algorithms which were used for experiment lower than that of pre-stored video data, except special case.

Spaceborne High Speed Data Link Design for Multi-Mode SAR Image Data Transmission

  • Kwag, Young-Kil
    • Journal of electromagnetic engineering and science
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    • v.2 no.1
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    • pp.39-44
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    • 2002
  • A high speed data link capability is one of the critical factors in determining the performance of the spaceborne SAR system with high resolution because of the strict requirement far the real-time data transmission of the massive SAR data in a limited time of mission. In this paper, based on the data lint model characterized by the spaceborne small SAR system, the high rate multi-channel data link module is designed including link storage, link processor, transmitter, and wide-angle antenna. The design results are presented with the performance analysis on the data link budget as well as the multi-mode data rate in association with the SAR imaging mode of operation from high resolution to the wide swath.

High-performance TDM-MIMO-VLC Using RGB LEDs in Indoor Multiuser Environments

  • Sewaiwar, Atul;Chung, Yeon-Ho
    • Current Optics and Photonics
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    • v.1 no.4
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    • pp.289-294
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    • 2017
  • A high-performance time-division multiplexing (TDM) -based multiuser (MU) multiple-input multipleoutput (MIMO) system for efficient indoor visible-light communication (VLC) is presented. In this work, a MIMO technique based on RGB light-emitting diodes (LEDs) with selection combining (SC) is utilized for data transmission. That is, the proposed scheme employs RGB LEDs for parallel transmission of user data and transmits MU data in predefined slots of a time frame with a simple and efficient design, to schedule the transmission times for multiple users. Simulation results demonstrate that the proposed scheme offers an approximately 6 dB gain in signal-to-noise ratio (SNR) at a bit error rate (BER) of $3{\times}10^{-5}$, as compared to conventional MU single-input single-output (SISO) systems. Moreover, a data rate of 66.7 Mbps/user at a BER of $10^{-3}$ is achieved for 10 users in indoor VLC environments.

Design of a Novel Multi-Dimensional HCOC Multi-code Spread Spectrum System Using Pre-coding Technique for High Speed Data Transmission of DS-CDMA

  • Kong, Hyung-Yun;Lee, Dong-Un
    • Journal of electromagnetic engineering and science
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    • v.7 no.1
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    • pp.1-6
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    • 2007
  • Recently, Mc(Multi-code) modulation/demodulation(modem) technique has been explored for high speed data transmission in wireless environment. The conventional Mc modem generates some side effects such as allocating Walsh codes, which motivates to propose a novel Mc modem method with sub-code. Our proposed system should expanded the size of sub-code to provide high-rate data transmission, which also affect adversely to the performance of the system with high PAPR(Peak to Average Power Ratio). Thus, in this paper, we propose a novel pre-coded Multi-Dimensional HCOC(High Capacity Orthogonal Code) Mc modem technique to reduce the high PAPR, which enables the performance improvement. This proposed system can be easily designed by concatenating HCOC Mc modem with the generic Mc modem. The pre-coding technique that is used in this paper is CAC(Constant Amplitude Coding), that helps the system maintain the constant transmission power and reduce the maximum transmission power.

Grouping of Wireless Terminals for High-Rate Transmission in Wireless LANs (무선랜에서 고속 데이터 전송을 위한 무선 단말들의 그룹화 알고리즘)

  • 우성제;이태진
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.3A
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    • pp.293-302
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    • 2004
  • Wireless LAN is a rather mature communication technology that connects mobile terminals. A typical wireless LAN system is composed of one AP and more than one terminals, which is called a BSS. Terminals near to an AP can receive high rate data but terminals far from an AP may not receive data with guaranteed high speed rate because received signal strength is weakened. This paper proposes a method to allow high speed data transmission by grouping terminals and using part of wireless terminals as repeaters. We compare and analyze proposed grouping algorithms based on Depth First Search and Breadth First Search via simulations. A grouping algorithm based on Breadth First Search is shown to be more effective in term of efficiency and coverage.