• Title/Summary/Keyword: wireless communication based

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Deep learning-based scalable and robust channel estimator for wireless cellular networks

  • Anseok Lee;Yongjin Kwon;Hanjun Park;Heesoo Lee
    • ETRI Journal
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    • v.44 no.6
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    • pp.915-924
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    • 2022
  • In this paper, we present a two-stage scalable channel estimator (TSCE), a deep learning (DL)-based scalable, and robust channel estimator for wireless cellular networks, which is made up of two DL networks to efficiently support different resource allocation sizes and reference signal configurations. Both networks use the transformer, one of cutting-edge neural network architecture, as a backbone for accurate estimation. For computation-efficient global feature extractions, we propose using window and window averaging-based self-attentions. Our results show that TSCE learns wireless propagation channels correctly and outperforms both traditional estimators and baseline DL-based estimators. Additionally, scalability and robustness evaluations are performed, revealing that TSCE is more robust in various environments than the baseline DL-based estimators.

Study on optimized positioning of wireless communication equipment for CBTC (CBTC를 위한 무선통신장비의 최적 위치 선정연구)

  • Kim Yun-Bae;Jung Jae-Ok
    • Proceedings of the KSR Conference
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    • 2004.10a
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    • pp.1199-1204
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    • 2004
  • In this paper, the DCS (Data Communication System) which is a main part of CBTC (Communication Based Train Control) system is consisted of radio based wireless communication system and optical based wired system. In the radio based wireless communication, the location of AP(Access Point) Enclosure and Antenna shall be optimized for the guaranteed communication channel between wayside and trains either open aired or tunnelled area. This study is introducing the way of determinating optimized positioning the radio based wireless communication equipment in Bundang Line. At this moment, this CBTC project for the KNR's (Korea National Railway) intelligent train control system are in installment phase therefore the simulation data can show only from lab equipment. After the phase I testing, more detailed data can be collected and advanced paper will be issued in a short time.

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A multiple PLC wireless communication module using master-slave control concept (Mastey-Slave 개념을 이용한 PLC용 다대다 통신 모듈 개발)

  • 박종석;현웅근;김이곤
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.48-48
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    • 2000
  • We developed a wireless communication system for multiple instrumentation system. The developed system has a function of remote instrumentation and PLC(Programmable Logic Controller) control. The system consists of CC(Control and Communication) protocol, wireless media access and physical media system. For multiple wireless communication, we propose a hub polling protocol based on master-slave control concept. To show the validity of the developed system, several experiments are illustrated.

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Demand-based charging strategy for wireless rechargeable sensor networks

  • Dong, Ying;Wang, Yuhou;Li, Shiyuan;Cui, Mengyao;Wu, Hao
    • ETRI Journal
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    • v.41 no.3
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    • pp.326-336
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    • 2019
  • A wireless power transfer technique can solve the power capacity problem in wireless rechargeable sensor networks (WRSNs). The charging strategy is a wide-spread research problem. In this paper, we propose a demand-based charging strategy (DBCS) for WRSNs. We improved the charging programming in four ways: clustering method, selecting to-be-charged nodes, charging path, and charging schedule. First, we proposed a multipoint improved K-means (MIKmeans) clustering algorithm to balance the energy consumption, which can group nodes based on location, residual energy, and historical contribution. Second, the dynamic selection algorithm for charging nodes (DSACN) was proposed to select on-demand charging nodes. Third, we designed simulated annealing based on performance and efficiency (SABPE) to optimize the charging path for a mobile charging vehicle (MCV) and reduce the charging time. Last, we proposed the DBCS to enhance the efficiency of the MCV. Simulations reveal that the strategy can achieve better performance in terms of reducing the charging path, thus increasing communication effectiveness and residual energy utility.

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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    • v.33 no.2
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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.

BACnet/ZigBee-based Lighting Control System (BACnet/ZigBee 프로토콜 기반의 조명제어시스템)

  • Chon, Y.J.;Park, T.J.;Park, D.K.;Hong, S.H.
    • Proceedings of the KIEE Conference
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    • 2006.10c
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    • pp.117-119
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    • 2006
  • BACnet(Building Automation and Control networks) is a standard data communication protocol designed specifically for building automation and control systems. BACnet provides five options for datalink layer protocols and these five datalink layer options can be applied with various transmission media. Recently wireless technology prevails in automation area. ZigBee is a standard protocol based on IEEE 802.15.4 for low-speed wireless communication network. In this study, we propose a BACnet/ZigBee model that uses ZigBee wireless technology in a BACnet communication network system as a wireless datalink layer protocol. We also applied this model to a lighting control system to evaluate the feasibility of proposed technology. The technology proposed in this paper can extend the application of BACnet not only for building automation but also for home automation by taking the advantages of ZigBee wireless communication technology in BACnet communication network systems.

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Study of applicable security tunneling technique for military wireless network (군 무선네트워크 환경에서 적용 가능한 보안 터널링 기법 연구)

  • Kim, Yun-young;Namkung, Seung-Pil
    • Convergence Security Journal
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    • v.15 no.4
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    • pp.107-112
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    • 2015
  • Due to the rapid development of wireless communication technology, foundation system of military communication that is based on the daily use technology has been changed in to wireless system. However, military communication contains clssified information, and it is expected to have increase amount of enemy's there in such a imperfect security system. The next generation of tactical network communication system is expected to adopt All IP based wireless system. This research studies expected threatening factor on the wireless environment, and find the appropriate tunneling techniques.

Performance Measurement of LTE based Railway Wireless Communication Systems in the Testbed (테스트베드상에서 LTE기반 철도 무선통신시스템의 성능 측정)

  • Kim, Bum-Gon;Kwon, Byung-Hee;Cho, Han-Byeog;Cho, Woong
    • The Journal of the Korea institute of electronic communication sciences
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    • v.12 no.5
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    • pp.755-762
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    • 2017
  • In railway communication, LTE based railway wireless communication systems have been developed to support high data rate and reliable communication link. In this paper, the testbed of LTE based railway wireless communication systems is introduced. Then, we describe measurement results of communication performance such as radiation strength, communication coverage, call setup time, handover success rate, and data transmission rate in the testbed. We also consider requirements for commercialization based on measurement results.

Technology Trends in Wireless Communication for Railway Systems (철도전용 무선통신 기술 동향)

  • Lee, S.J.;Oh, S.C.;Yoon, B.S.;Jeong, H.S.
    • Electronics and Telecommunications Trends
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    • v.36 no.4
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    • pp.23-33
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    • 2021
  • Wireless communication for train control is an active research field. The World Railway Federation in Europe developed GSM-R, which integrates the GSM-based voice call standard and train control signals. To provide advanced railway services, the LTE-R wireless communication system was developed in Korea for passenger services and wireless image information required by the railroad industry. Recently, direct communication technology for autonomous train driving has been studied to decrease the driving interval, and research is being conducted on a hyperloop train control system that runs at a maximum speed of 1,220km/h in a subvacuum environment of 0.001 atmosphere. In this paper, we summarize the trends in wireless communication technologies used for GSM-R/LTE-R railway systems. For future wireless communication in railway systems, we discuss autonomous train driving and the hyperloop railway control system, define wireless communication technology, and discuss trends in domestic and foreign technologies.

Wireless Communication System for T/C based on DSRC (DSRC 기반의 T/C 무선통신 시스템 개발)

  • 성창우;강대성
    • Journal of Korean Port Research
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    • v.14 no.3
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    • pp.313-319
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    • 2000
  • In this paper, we proposed the model of wireless communication for ACTS using DSRC and the DSRC system for T/C. The proposed wireless communication model is how to join with DSRC and other wireless communication in port. The DSRC system for T/C is the first application to the unit of port Facilities Automation on stacking area. The DSRC system is communicated between OBE and RSE using 5.8Hz ISM band frequency. The previous works of DSRC applications are gate automation. In these cases, the road trackers are difficult to obtain information of the port in the stacking area. So we used the DSRC for the wireless communication for the port Facilities Automation. Using DSRC, the load trackers obtain more information in the port and contacts to ITS on back-roads of port. The proposed communication system is serviced to reelection of port statistics.

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