• Title/Summary/Keyword: digital communication

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Design of the digital TRS network for for the Distribution Automation System (디지털 TRS를 이용한 배전자동화통신망 구축 방안)

  • Kim, Tae-Gyeong
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.420_421
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    • 2009
  • The digital TRS(Trunked Radio System) is an excellent alternative for the transmission medium for the DAS(Distribution Automation System). KEPCO(Korea Electric Power Corporation) made the power IT network with digital TRS system. The main function of the radio network is transmitting and receiving information for the DAS. KEPCO's digital TRS is based on TETRA standard. The digital TRS supports data communication for the electric power control and monitoring systems in various ways.

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Digital Multisignature Schemes in Electronic Contract Systems (전자 계약시스템에서의 디지털 다중서명 방식)

  • 강창구;김대영
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.31A no.1
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    • pp.17-25
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    • 1994
  • We analyze risks andd present the requirements of digital multisignature in electronic contract systems where several persons contract a digital document electronically. We also apply a few digital multisignature schemes that have been developed so far, to the electronic contract system and propose a new digital multisignature scheme based on the Fiat-Shamir scheme. We investigate how these schemes satisfy with the requirements and evaluate their efficiency in terms of processing speed. communication complexity, and message length Owing to the high processing speed and the high degree of satisfaction to the requirements, the proposed scheme is suitable for electronic contract systems.

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Integral TS Demultiplexer of Memory Sharing based DVB-T/T-DMB Receiver (메모리공유 기반의 DVB-T/T-DMB 통합 TS의 역다중화기)

  • Kwon, Ki-Won;Paik, Jong-Ho;Kang, Min-Goo
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.10 no.6
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    • pp.17-22
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    • 2010
  • In this paper, integral TS(Transport Stream) demultiplexer of a multi-modal receiver is proposed according to the multiple standards of European terrestrial digital broadcasting DVB-T(Digital Video Broadcasting Terrestrial), and mobile terrestrial digital broadcasting T-DMB(Terrestrial Digital Multimedia Broadcasting). This USB based integral receiver could recover the multi-modal broadcasting audios by memory sharing technique which was utilized to decrease the load by the control of streaming multi-modal broadcasting. As a result of performance analysis for a proposed integral TS demultiplexer, the CPU occupational efficiency of windows based integral demulitiplexing is improved compared with DVB-T, and T-DMB respectively.

An Improved Joint Detection of Frame, Integer Frequency Offset, and Spectral Inversion for Digital Radio Mondiale Plus

  • Kim, Seong-Jun;Park, Kyung-Won;Lee, Kyung-Taek;Choi, Hyung-Jin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.2
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    • pp.601-617
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    • 2014
  • In digital radio broadcasting systems, long delays are incurred in service start time when tuning to a particular frequency because several synchronization steps, such as symbol timing synchronization, frame synchronization, and carrier frequency offset and sampling frequency offset compensation are necessary. Therefore, the operation of the synchronization blocks causes delays ranging from several hundred milliseconds to a few seconds until the start of the radio service after frequency tuning. Furthermore, if spectrum inversed signals are transmitted in digital radio broadcasting systems, the receivers are unable to decode them, even though most receivers can demodulate the spectral inversed signals in analog radio broadcasting systems. Accordingly, fast synchronization techniques and a method for spectral inversion detection are required in digital radio broadcasting systems that are to replace the analog radio systems. This paper presents a joint detection method of frame, integer carrier frequency offset, and spectrum inversion for DRM Plus digital broadcasting systems. The proposed scheme can detect the frame and determine whether the signal is normal or spectral inversed without any carrier frequency offset and sampling frequency offset compensation, enabling fast frame synchronization. The proposed method shows outstanding performance in environments where symbol timing offsets and sampling frequency offsets exist.

Smart Home Environment for the Protection of Multimedia Digital Contents (멀티미디어 콘텐츠 보호를 위한 스마트 홈 환경)

  • Choi, Kee-Hyun;Jang, Kyung-Soo;Shin, Ho-Jin
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.11 no.2
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    • pp.189-196
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    • 2011
  • As internet is getting advanced day by day, digital contents have been developed in various areas as killer content in the IT industry. It needs to develop lots of complicated digital content protect systems due to the enhancement and variety of user's multimedia devices. Although there are lots of protect systems based on DRM(Digital Rights Management) technology, it is difficult to provide secure protection because of the problems resulting from analog hole problem, inefficiency of key sharing and various independent protect technologies. Thus, in this paper, we propose a novel authentication and protect system based on RFID(Radio Frequency Identification) technology to solve the problems and show possibility of free content duplication and efficient contents management in smart home environments.

Study on Design of Digital filter by 2's Complement Representation using Bidirectional algorithm (양방향 알고리즘을 이용한 2의 보수 표현 기법에 의한 디지털 필터의 설계에 관한 연구)

  • LEE, Youngseock
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.2 no.1
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    • pp.37-42
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    • 2009
  • The digital filter is essential element in digital signal processing area. It needs a high computational burden caused by multiplying and adding. The multiplier in digital filter is a dominant element, which occupies an wide area at the field of VLSI design, needs high power-consuming and also decides critical path that affects to filter performance. In this paper we proposed the simultaneous transform method which is represented 2's complementary representation to CSD and MSD representation to solve a complexity problem and to improve a computational speed. The performance of proposed method was implemented in VHDL and applied to an digital filters, was evaluated the decreasing of critical path delay.

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