• Title/Summary/Keyword: mRelay

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Implementation of Multimedia Services in a Mobile Ad-hoc Network (이동 Ad-hoc 네트워크에서의 멀티미디어 서비스 구현)

  • Ro Kwang-Hyun;Kwon Hye-Yeon;Shin Jae-Wook;Park Ae-Soon
    • Journal of the Institute of Convergence Signal Processing
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    • v.7 no.2
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    • pp.45-52
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    • 2006
  • Mobile Ad-hoc Network(MANET) could be applied to various applications by virtue of its characteristics such as self-organizing and infrastructure-free network. This paper proposes a multimedia application service model for MANET, called multi-hop Relay(mRelay) system. It supports a multi-hop communication-based multimedia service interworked with Internet by using an unmanned moving robot with wireless multimedia communication function as a mRelay terminal. The modified AODV routing protocol was applied to the terminal and it was verified that composition and maintenance of mobile Ad-hoc network in mRelay system under the various indoor scenarios were successful and stable multi-hop multimedia services were possible. The mRelay system can be applicable to various application services of mobile Ad-hoc networks.

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Exact Performance Analysis of AF Based Hybrid Satellite-Terrestrial Relay Network with Co-Channel Interference

  • Javed, Umer;He, Di;Liu, Peilin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.9
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    • pp.3412-3431
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    • 2015
  • This paper considers the effect of co-channel interference on hybrid satellite-terrestrial relay network. In particular, we investigate the problem of amplify-and-forward (AF) relaying in hybrid satellite-terrestrial link, where the relay is interfered by multiple co-channel interferers. The direct link between satellite and terrestrial destination is not available due to masking by surroundings. The destination node can only receive signals from satellite with the assistance of a relay node situated at ground. The satellite-relay link is assumed to follow the shadowed Rice fading, while the channels of interferer-relay and relay-destination links experience Nakagami-m fading. For the considered AF relaying scheme, we first derive the analytical expression for the moment generating function (MGF) of the output signal-to-interference-plus-noise ratio (SINR). Then, we use the obtained MGF to derive the average symbol error rate (SER) of the considered scenario for M-ary phase shift keying (M-PSK) constellation under these generalized fading channels.

Development of PCM Current Differential Relay Setting Module Using UML (UML(Unified Modeling Language)기법을 이용한 PCM전류차동계전기 정정모듈 개발)

  • Oh, T.W.;Oh, S.M.;Min, B.U.;Lee, S.J.;Choi, M.S.
    • Proceedings of the KIEE Conference
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    • 2003.07a
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    • pp.329-331
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    • 2003
  • PROSET2000 that is integrated protective management system had developed and used in order to automate the setting process of protective relays in transmission system protection. PROSET2000 have database for relay setting and automated for relay setting program within. This paper proposed PCM current differential relay setting program point of Object Oriented Programming paradigm using Unified Modeling Language about additional relay in PROSET2000. Nevertheless each relay uses same current differential but setting method is different. This paper discribed different thing about setting method of each relay and evaluated more effective and corrective relay setting program using UML.

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Network-Coding Based Two-way Relay Communication Using Adaptive Modulation Sheme (적응형 변조 기법을 이용한 네트워크 부호화 기반 양방향 중계 통신)

  • Lee, Jin-Hee;Kong, Hyung-Yun
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.10 no.5
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    • pp.147-151
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    • 2010
  • In this paper, we propose network-coding based two-way relay communication using adaptive modulation scheme for satisfying relay QoS(Quality of Service) according to channel environment between user and relay. Two-way relay communication is bidirectional cooperative communication that users exchange own signal with help of relay. Network-coding based two-way relay communication can achieve high throughput compared to conventional scheme through reducing time slots. we propose adaptive M-QAM modulation scheme in network-coding based two-way relay communication for satisfying QoS of relay. Simulation result shows that the proposed scheme satisfies goal QoS of system.

Degrees of Freedom of 3-user MIMO Interference Channels with Instantaneous Relay Using Interference Alignment

  • Qiang, Wang;Yuquan, Shu;Minhua, Dong;Ji, Xu;Xiaofeng, Tao
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.5
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    • pp.1624-1641
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    • 2015
  • Instantaneous relay (relay-without-delay) using interference alignment is a promising approach to neutralizing interference and improving system capacity. In Wang Chenwei's work, a 2-user scenario required both source and relay to access the global channel state information (CSI). This paper shows a new method of interference alignment improves the degrees of freedom (DoF) prominently for the 3-user MIMO interference channel with instantaneous relay. This new method is focused on the relay node that completes the alignment interference neutralization so the global CSI is obtained only once and the pressure on the base station can be mitigated. In addition, the 3-user MIMO interference channels with instantaneous relay can achieve 2M DoF when source and destination have M antennas, respectively. This method shows 33% improvement over the conventional method using interference alignment which obtains 3M/2 DoF.

Analysis and Simulator Design of Portable Microwave Digital FPU Transmission System (M/W대역 디지털 방송중계용 FPU 무선전송 시스템 분석과 시뮬레이터 설계)

  • 강희조;조성언;최용석
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.7 no.4
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    • pp.658-666
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    • 2003
  • In this paper, we analyzed standard and characteristic of portable microwave digital FPU(Field Pick Up) transmission system in AWGN channel environment as basis step of research about share way of M/W broadcasting relay frequency. And we analyzed system performance through simulator design. Domestic case, digitize progress about broadcasting relay is propeled. Therefore, we wish to utilize to basis data about interference evaluation and domestic broadcasting relay standardization for reassignment of M/W band broadcasting relay frequency.

Exact and Approximate Symbol Error Probability of cooperative systems with best relay selection and all participating relaying using Amplify and Forward or Decode and Forward Relaying over Nakagami-m fading channels

  • Halima, Nadhir Ben;Boujemaa, Hatem
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.1
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    • pp.81-108
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    • 2018
  • In this paper, we derive the theoretical Symbol Error Probability (SEP) of cooperative systems with best relay selection for Nakagami-m fading channels. For Amplify and Forward (AF) relaying, the selected relay offers the best instantaneous Signal to Noise Ratio (SNR) of the relaying link (source-relay-destination). In cooperative networks using Decode and Forward (DF), the selected relay offers the best instantaneous SNR of the link between the relay and the destination among the relays that have correctly decoded the transmitted information by the source. In the second part of the paper, we derive the SEP when all participating AF and DF relaying is performed. In the last part of the paper, we extend our results to cognitive radio networks where there is interference constraints : only relays that generate interference to primary receiver lower than a predefined threshold T can transmit. Both AF and DF relaying with and without relay selection are considered.

Autonomous Adaptive Digital Over Current Relay (계통변화를 고려한 자율 적응형 과전류 계전기)

  • J.S., Jun-Seok;Lee, S.J.;Choi, M.S.;Kang, S.H.;Kim, S.T.;Lim, S.I.;Oh, S.M.;Kim, J.K.;Park, S.J.
    • Proceedings of the KIEE Conference
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    • 2002.07a
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    • pp.6-8
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    • 2002
  • In this paper present Autonomous Adaptive Digital Over Current Relay which acts autonomous setting using voltage and current measured by relay in the change of power systems. Automation of relay setting is required for distribution automation although manual relay setting is used at present. This paper presents Autonomous Relay Setting which knows change of the power system and acquires setting element using the Recursive Least Squares. Relay setting is very difficult work. But proposed relay is expected to decrease burden of relay setting using acquired information of power system change and autonomous setting. Also fast protective ability is expected according to change of power system.

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Performance Analysis of Nonlinear Energy-Harvesting DF Relay System in Interference-Limited Nakagami-m Fading Environment

  • Cvetkovic, Aleksandra;Blagojevic, Vesna;Ivanis, Predrag
    • ETRI Journal
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    • v.39 no.6
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    • pp.803-812
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    • 2017
  • A decode-and-forward system with an energy-harvesting relay is analyzed for the case when an arbitrary number of independent interference signals affect the communication at both the relay and the destination nodes. The scenario in which the relay harvests energy from both the source and interference signals using a time switching scheme is analyzed. The analysis is performed for the interference-limited Nakagami-m fading environment, assuming a realistic nonlinearity for the electronic devices. The closed-form outage probability expression for the system with a nonlinear energy harvester is derived. An asymptotic expression valid for the case of a simpler linear harvesting model is also provided. The derived analytical results are corroborated by an independent simulation model. The impacts of the saturation threshold power, the energy-harvesting ratio, and the number and power of the interference signals on the system performance are analyzed.

Security Performance Analysis of DF Cooperative Relay Networks over Nakagami-m Fading Channels

  • Zhang, Huan;Lei, Hongjiang;Ansari, Imran Shafique;Pan, Gaofeng;Qaraqe, Khalid A.
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.5
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    • pp.2416-2432
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    • 2017
  • In this paper, we investigate the security performance for cooperative networks over Nakagami-m fading channels. Based on whether the channel state information (CSI) of wiretap link is available or not, optimal relay selection (ORS) and suboptimal relay selection (SRS) schemes are considered. Also, multiple relays combining (MRC) scheme is considered for comparison purpose. The exact and asymptotic closed-form expressions for secrecy outage probability (SOP) are derived and simulations are presented to validate the accuracy of our proposed analytical results. The numerical results illustrate that the ORS is the best scheme and SRS scheme is better than MRC scheme in some special scenarios such as when the destination is far away from the relays. Furthermore, through asymptotic analysis, we obtain the closed-form expressions for the secrecy diversity order and secrecy array gain for the three different selection schemes. The secrecy diversity order is closely related to the number of relays and fading parameter between relay and destination.