• Title/Summary/Keyword: wireless D2D communication

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Development of 3-D viewer for indoor location tracking system using wireless sensor network

  • Yang, Chi-Shian;Chung, Wan-Young
    • Journal of Sensor Science and Technology
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    • v.16 no.2
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    • pp.110-114
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    • 2007
  • In this paper we present 3-D Navigation View, a three-dimensional visualization of indoor environment which serves as an intuitive and unified user interface for our developed indoor location tracking system via Virtual Reality Modeling Language (VRML) in web environment. The extracted user's spatial information from indoor location tracking system was further processed to facilitate the location indication in virtual 3-D indoor environment based on his location in physical world. External Authoring Interface (EAI) provided by VRML enables the integration of interactive 3-D graphics into web and direct communication with the encapsulated Java applet to update position and viewpoint of user periodically in 3-D indoor environment. As any web browser with VRML viewer plug-in is able to run the platform independent 3-D Navigation View, specialized and expensive hardware or software can be disregarded.

Packet Off-Loading Scheme Using a Femto-Cell Local Gateway and D2D Communication at Remote Shipyards (원격 조선소의 펨토셀 로컬 게이트웨이와 D2D 통신 기술을 이용한 패킷 오프로드 방식)

  • Han, Kyeongil;Cho, Yongcheon;Lee, Seongro;Min, Sangwon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39C no.11
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    • pp.1139-1145
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    • 2014
  • In shipyard site, a ship is constructed by integrating lots of modules that are made in several sites with different capabilities and specifications. Recently, it needs to make a shipyard to be smart communicating various multimedia information with wired and wireless broadband networks between hierarchical shipyards. In this paper, we propose an additional function of an LTE femtocell local gateway at a remote shipyard, an information exchange method between hierarchical shipyards, and an offload method to separate the general traffic. To reduce traffic of duplicated requests in shipyard, we apply a D2D communication scheme for supporting communication between shipyard equipments without IP service network. Hence, it is expected to increase the productivity of shipyard industry with mobile communications, D2D and broadband Internet technologies.

Dual band antenna design for LTE / WLAN for wireless mobile communication high-speed network (무선 이동통신 고속 통신망을 위한 LTE/WLAN용 이중대역 안테나 설계)

  • Kim, Gyeong-rok;Oh, Mal-geun
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2018.10a
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    • pp.517-521
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    • 2018
  • In this paper, we designed a microstrip antenna for LTE / WLAN for wireless mobile communication high - speed communication network. The substrate of the proposed antenna is FR-4 (er = 4.3), the size is $20[mm]{\times}40[mm]$ and can be used in the frequency band of 2.77 [GHz] and 5 [GHz] Respectively. The simulation was performed using CST Microwave Studio 2014. The simulation result shows that the gain is 2.034 [dBi] at 2.77 [GHz] and 4.95 [dBi] at 5 [GHz]. The S-parameter was also found to be less than -10 [dB] (WSWR 2: 1) in the desired frequency band. The frequency bands of LTE and WLAN are widely used around the world, and the usage of the frequency is also increasing. For this reason, the dual-band antenna of LTE / WLAN is designed to help many users in a good way to use both technologies.

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Design of High Efficiency Switching Mode Class E Power Amplifier and Transmitter for 2.45 GHz ISM Band (2.45 GHz ISM대역 고효율 스위칭모드 E급 전력증폭기 및 송신부 설계)

  • Go, Seok-Hyeon;Koo, Kyung-Heon
    • Journal of Advanced Navigation Technology
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    • v.24 no.2
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    • pp.107-114
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    • 2020
  • A power amplifier of 2.4 GHz ISM band is designed to implement a transmitter system. High efficiency amplifiers can be implemented as class E or class F amplifiers. This study has designed a 20 W high efficiency class E amplifier that has simple circuit structure in order to utilize for the ISM band application. The impedance matching circuit was designed by class E design theory and circuit simulation. The designed amplifier has the output power of 44.2 dBm and the power added efficiency of 69% at 2.45 GHz. In order to apply 30 dBm input power to the designed power amplifier, voltage controlled oscillator (VCO) and driving amplifier have been fabricated for the input feeding circuit. The measurement of the power amplifier shows 43.2 dBm output and 65% power added efficiency. This study can be applied to the design of power amplifiers for various wireless communication systems such as wireless power transfer, radio jamming device and high power transmitter.

Design of Dual LTE-band MIMO Antenna (이중 LTE 대역의 MIMO 안테나 설계)

  • Choi, Won-Sang;Lee, Hong-Min
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.4 no.1
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    • pp.46-52
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    • 2011
  • In the paper, MIMO antenna for LTE 13 band, LTE 7 band wireless communication service is proposed. The proposed antenna is designed where on the top of FR-4(${\epsilon}_r=4.4$, thickness=-.8mm). In proposed structure, two Planar Inverted F Antennas (PIFAs) using meander and folded structure are symmetrically designed for the miniaturization. The isolation between two antennas was also improved by using two slits on the ground plane. The isolation values of the fabricated antenna exhibits -18 dB, -13dB at LTE 13 and LTE 7 band, respectively. The average gain and efficiency are - 4.1 dBi, 41% on LTE 13 band, -1 dBi, 81% on LTE 7 band, respectively. Thus the proposed antenna can be applied to the LTE system.

Modeling and Evaluation of Wireless Communication System using CSMA inthe Distributed Packet Radio Network (분산 무선망에서 CSMA를 사용한 무선 통신 시스템의 모델링 및 성능 분석)

  • 조병록;최형진;박병철
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.18 no.10
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    • pp.1508-1517
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    • 1993
  • In this paper, we propose the modeling of a wireless communication system using CSMA protocol, present analytical evalution and simulation as a function of arrival rate and mean END-to-END delay in the distributed packet radio network. Asynchronous 1-persistent CSMA protocol is used in wireless communication system with half duplex. We assume that all terminals are to be in the close range of each other, suitably located in the local area. The traffic presented to a common channel is assumed to be poisson distribution. Analytical model is based on a M/D/1 with breakdown. In conclusion for wireless network model proposed in this paper is suitable for packet arrival rate of 2 packet/sec with mean packet delay time less than 2 times the packet transmission time.

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Analysis Third-dimension Turbo Code for DVB-RCS Next Generation (DVB-RCS Next Generation을 위한 Third-dimension Turbo Code 분석)

  • Park, Tae-Doo;Kim, Min-Hyuk;Jung, Ji-Won
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.15 no.2
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    • pp.279-285
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    • 2011
  • The next generation wireless communication systems are required high BER performance better than present performance. Double binary Turbo code have error floor at high SNR, so it cannot be used in next generation wireless communication system. Therefore, many methods are proposed for overcome error floor at DVB-RCS NG(next generation). In this paper, we analysis structure of third-dimension Turbo code(3D-turbo code). 3D-Turbo code overcomes error flow by additive post-encoder in conventional DVB-RCS Turbo code. Performance of 3D-Turbo code is changed by post-encoder form, interleaving method, value of ${\lambda}$. So we are simulated by those parameter and proposed optimal form. By a result, performance of 3D-Turbo is better than conventional DVB-RCS Turbo code and it overcome error floor of conventional DVB-RCS Turbo code.

Subcarrier Intensity Modulation-Spatial Modulation for Optical Wireless Communications (광 무선통신을 위한 SIM-SM 변조)

  • Cheng, Yan;Hwang, Seung-Hoon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38A no.12
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    • pp.1086-1093
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    • 2013
  • In this paper, we propose a novel modulation that combines the spatial modulation (SM) with the subcarrier intensity-modulation (SIM) for optical wireless communications. The performance of SIM-SM scheme is compared to a conventional SIM by computer simulation. For the spectral efficiency (SE) of 2bits/s/Hz, the performance gain about 2dB is achieved. As the SE increases to 3bit or 4bits/s/Hz, the Eb/N0 gain becomes about 5dB. It is shown the attenuation for the SIM is more serious than the SIM-SM according to increasing the number of the subcarriers.

Link Performance Analysis for Intra-Aircraft Wireless Communications in 4.4GHz (4.4GHz 대역을 활용한 항공기내 무선통신 링크 성능 분석)

  • Cho, Moon-Je;Jung, Bang Chul;Park, Pangun;Chang, Woohyuk;Ban, Tae-Won
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.7
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    • pp.1243-1248
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    • 2016
  • This paper investigated the channel link budget for Wireless Avionics Intra-Communication (WAIC) in 4.4GHz. The band 4.2~4.2GHz was allocated for the communication service among aeronautical applications in world radiocommunication conference (WRC). Wireless channels in aircraft was modelled by the combination of path loss, shadowing effect caused by obstacles, and fading caused by multipath signals. In addition, wireless channels in aircraft are categorized into 6 groups according to various locations of transmitter and receiver. We analyzed the channel link budget for the 6 channel groups in terms of maximum transmission distance and outage probability. Our analysis and intensive computer simulation results show that the propagation characteristics of group A, B, and F is superior to group C, D, E, and the propagation of group E is the most vulnerable. Also, these results can be utilized as basic reference for the channel analysis of intra-aircraft or similar environment.

Research on Intelligent Anomaly Detection System Based on Real-Time Unstructured Object Recognition Technique (실시간 비정형객체 인식 기법 기반 지능형 이상 탐지 시스템에 관한 연구)

  • Lee, Seok Chang;Kim, Young Hyun;Kang, Soo Kyung;Park, Myung Hye
    • Journal of Korea Multimedia Society
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    • v.25 no.3
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    • pp.546-557
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    • 2022
  • Recently, the demand to interpret image data with artificial intelligence in various fields is rapidly increasing. Object recognition and detection techniques using deep learning are mainly used, and video integration analysis to determine unstructured object recognition is a particularly important problem. In the case of natural disasters or social disasters, there is a limit to the object recognition structure alone because it has an unstructured shape. In this paper, we propose intelligent video integration analysis system that can recognize unstructured objects based on video turning point and object detection. We also introduce a method to apply and evaluate object recognition using virtual augmented images from 2D to 3D through GAN.