• 제목/요약/키워드: Communication Systems

검색결과 11,893건 처리시간 0.044초

Compressed Sensing-Based Multi-Layer Data Communication in Smart Grid Systems

  • Islam, Md. Tahidul;Koo, Insoo
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제7권9호
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    • pp.2213-2231
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    • 2013
  • Compressed sensing is a novel technology used in the field of wireless communication and sensor networks for channel estimation, signal detection, data gathering, network monitoring, and other applications. It plays a significant role in highly secure, real-time, well organized, and cost-effective data communication in smart-grid (SG) systems, which consist of multi-tier network standards that make it challenging to synchronize in power management communication. In this paper, we present a multi-layer communication model for SG systems and propose compressed-sensing based data transmission at every layer of the SG system to improve data transmission performance. Our approach is to utilize the compressed-sensing procedure at every layer in a controlled manner. Simulation results demonstrate that the proposed monitoring devices need less transmission power than conventional systems. Additionally, secure, reliable, and real-time data transmission is possible with the compressed-sensing technique.

기존 전술 무전기를 이용한 전술 데이터 통신 성능 실험 (The Performance Experiments on the Tactical Data Communication over the Legacy Radio Systems)

  • 심동섭;강경성;김기형
    • 한국군사과학기술학회지
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    • 제13권2호
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    • pp.243-251
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    • 2010
  • The military has been putting great efforts into applying data communication on existing voice communication systems being used in NCW(Network Centric Warfare). Data communication will be an effective choice in one of many effort to yield a minimum kill chain, comparing to legacy voice communications, when tactical units conduct their missions. However, the required budget will be enormous, in case of the replacement of a lot of legacy communication systems with new one. As a cost-effective alternative, the tactical data communication systems using the conventional radio systems instead of the development of new radio systems has been proposed. It is mandatory, though, to ensure QoS while maintaining data communication by making use of legacy radio systems already in use. This paper focuses on the performance issues experimented and analyzed for tactical data communication through the legacy radio systems as the first step towards guaranteed QoS. We have conducted various experiments such as the transmission error rate on certain tactical messages, performance evaluation of redundant transfers, the relationship between the transmission frame size and rate of error, the identification of error points in the transmission frame, and techniques to reduce the errors in both hopping and non-hopping modes. As a result of the performance experiments, The adaptive communication module which decides the redundant transmission or the Forward Error Correction(FEC) technique by analyzing channel status and current transmission status(hopping/non-hopping) of the legacy radio should be designed. the FEC technique in non-hopping, and the redundant transmission technique in hopping mode was recommended from the result of experiment with the frame size is 20bytes in non-hopping and 10Bytes frame size in hopping mode.

The performance of MIMO cooperative communication systems using the relay with multi-antennas and DSTC

  • Chan Kyu Kim
    • International Journal of Internet, Broadcasting and Communication
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    • 제15권3호
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    • pp.14-23
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    • 2023
  • The cooperative communication systems using MIMO(multiple input multiple-output) relay are known as one of the most promising techniques to improve the performance and coverage of wireless communication systems. In this paper, we propose the cooperative communication systems using the relay with multi-antennas and DSTC(distributed space time coding) for decode-and-forward protocol. As using DSTC for DF(decode-and-forward), we can minimize the risk of error propagation at the wireless system using relay system. Also, the MIMO channel cab be formed by multi-antenna and DSTC at the MS(mobile station)-RS(relay station) and at the RS-BS(base station).Therefore, obtaining truly constructive the MIMO diversity and cooperative diversity gain from the proposed approach, the performance of system can be more improved than one of conventional system (relay with single antenna, no relay). The improvement in bit error rate is investigated through numerical analysis of the cooperative communication system with the proposed approach.

우리별 1, 2호 통신시스템 (KITSAT-1/2 COMMUNICATION SYSTEM)

  • 민승현;명로훈;최순달
    • Journal of Astronomy and Space Sciences
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    • 제13권2호
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    • pp.82-93
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    • 1996
  • The paper discusses the design and construction of KITSAT-1/2 communication systems. Several requirements for the communication system have been analyzed and the specifications for KITSAT-1/2 communication systems have been summarized. Also the design and performance of KITSAT-1/2 communication system is described.

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A Study on Mobile Communication system using Stillness Image

  • Lee, Jung-Ho;Han, Dae-Mun;Kim, Yeong-Real
    • 한국산업정보학회:학술대회논문집
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    • 한국산업정보학회 2007년도 춘계학술대회
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    • pp.35-39
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    • 2007
  • We applied digital image processing about BitMap file structure in this research and studied about digital communication system. digital record saving devices can express 'High' and 'Low' as all data. Only, digital technique that two expression methods is used into several expenditures. People and communication that are far away by development of digital technology, became smooth. We wished to make communication system taking advantage of digi-tech. This system was made for communication with disabled and normal person specially. To communication method that we are studied such BitMap file handling image communication system. The goal of this contribution is to present the overview of basic algorithms for image processing using BitMap.

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Coexistence of OFDM-Based IMT-Advanced and FM Broadcasting Systems

  • Shamsan, Zaid A.;Rahman, Tharek A.;Kamarudin, Muhammad R.;Al-Hetar, Abdulaziz M.;Jo, Han-Shin
    • ETRI Journal
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    • 제33권2호
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    • pp.279-282
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    • 2011
  • Coexistence analysis is extremely important in examining the possibility for spectrum sharing between orthogonal frequency-division multiplexing (OFDM)-based international mobile telecommunications (IMT)-Advanced and other wireless services. In this letter, a new closed form method is derived based on power spectral density analysis in order to analyze the coexistence of OFDM-based IMT-Advanced systems and broadcasting frequency modulation (FM) systems. The proposed method evaluates more exact interference power of IMT-Advanced systems in FM broadcasting systems than the advanced minimum coupling loss (A-MCL) method. Numerical results show that the interference power is 1.3 dB and 3 dB less than that obtained using the A-MCL method at cochannel and adjacent channel, respectively. This reduces the minimum separation distance between the two systems, which eventually saves spectrum resources.

철도신호설비 상호간 정보전송을 위한 통신 프로토콜 검증시험 (Verification Test of Communication Protocol for Interface between EIS and LDTS)

  • 황종규;이재호;윤용기;신덕호
    • 한국철도학회논문집
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    • 제7권2호
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    • pp.114-119
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    • 2004
  • According to the computerization of railway signalling systems. the communication protocol for interface between these systems are required. Therefore the new communication protocol for railway signaling system is required. Generally, there are two verification method for new designed protocol in the industrial and academic fields. One is the laboratory testing method which is very popular and general technique. In our research the comparison between existing and new designed protocol for signaling is described and the verification test results are also represented. From these laboratory test, we are verified the conformance of new designed protocol. Another method is verified by formal method. The format verification method is widely used at safety-critical system design but this approach is nor popular at verification communication protocol. However it is very important to verify the safety of new designed protocol for railway signaling system because signaling systems are very safety-critical systems. So, the methodology for formal verification of designed protocol is also reviews in this paper.

분산 객체지향 시스템을 위한 정형 명세 방법에 관한 연구 (Formal Specification Methods for Distributed Object-Oriented Systems)

  • 이상범
    • 한국정보처리학회논문지
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    • 제7권5호
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    • pp.1426-1433
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    • 2000
  • As distributed computing systems become popular, many modeling techniques and methods have been developed in specify the specification formally and verify the distributed/concurrent sytems. In spite of importance of communication in distributed object-oriented systems, specifying of communication method generally has not been emphasized in the design phase. One reason is due to the system designer misunderstanding, that is, a specification needs to be independent on the implementation. However, since defining communication pattern indistributed object-oriented systems is more serious than the required message passing method in the design phase. specifying the communication pattern is necessary instead of postponing until the implementation. In this paper, two formal specification techniques, temporal logic method and Petri nets method, for the communication in distributed systems are discussed. One is based on the temporal logic, which specifies the different patterns of primitive predicates. This method enable to define the underlying mechanism which can be interpreted as constraints. The Petri net method helps to specify the dynamic behavior of communicational patterns using the properties of Petri nets.

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