• Title, Summary, Keyword: optical wireless communications

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Design of 2-dimensional trackling optical receiver systems for optical wireless mobile communications (광 무선 이동통신용 2차원 추적 광학 수신계 설계)

  • Park, Seung-Hyun;Lee, Dong-Suk;Kim, Kyung-Hun;Lee, Ill-Hang
    • Proceedings of the Optical Society of Korea Conference
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    • pp.28-29
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    • 2004
  • Optical wireless mobile communications have the potential to provide wide bandwidth and security . We have proposed and designed the 2-dimensional tracking optical receiver systems for optical wireless mobile communication. The receiver system consist of 4${\times}$4 photodiode array can receive optical signal from the transmitter. The room size is 5${\times}$5m$^2$ and the room height is 3m.

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Quality Analysis of Wireless Communication Channel Based on the Shapes of LED-Based Interior Lighting (LED기반 실내 조명 구조에 따른 무선통신 채널의 품질 분석)

  • Choi, Su-Il
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37 no.7B
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    • pp.606-612
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    • 2012
  • Visible light communications (VLC) uses modern solid-state LEDs to broadcast information. Emerging white-light LEDs allows the combination of lighting and optical wireless communication in one optical source. In this paper, a new LED lighting using one-chip-type white LED is proposed for efficient illumination and optical wireless communications. Performance analysis such as horizontal illuminance, 3-dB cut-off frequency, inter-symbol interference, signal-to-noise ratio and bit-error rate shows the effects of the shapes of LED lighting. Performance of the proposed LED lighting under the existence of obstacles is superior to that of the existing LED lighting in illumination and optical wireless communication.

New Type of White-light LED Lighting for Illumination and Optical Wireless Communication under Obstacles

  • Choi, Su-il
    • Journal of the Optical Society of Korea
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    • v.16 no.3
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    • pp.203-209
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    • 2012
  • Visible light communications (VLC) use modern solid-state light-emitting diodes (LEDs) to broadcast information. Emerging white-light LEDs allow the combination of lighting and optical wireless communication in one optical source. In this paper, a new LED lighting design using one-chip-type white LEDs is proposed for efficient illumination and optical wireless communications under the existence of several obstacles. Lighting and communication performance are analyzed to show the effectiveness of the proposed LED lighting. Specifically, the signal-to-noise ratio considering intersymbol interference and the bit-error rate of variable pulse position modulation (VPPM) with dimming control are considered.

Optical Camera Communications: Future Approach of Visible Light Communication

  • Le, Nam-Tuan;Nguyen, Trang;Jang, Yeong Min
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.2
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    • pp.380-384
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    • 2015
  • As an extension of Visible Light Communication, Optical Camera Communications (OCC) will be a promising service for smart devices. Especially in line of sight marketing service and indoor localization application, by using camera which exists in smart devices, small amount of data (url link) can be broadcasted or find direction from the illumination system. This paper introduces the operation of wireless communications technology that transmits optical information from optical light source to camera, called Optical Camera Communications.

Development of optical dual-sensors for submersion monitoring using zigbee-based wireless sensor networks (지그비 기반 센서 네트워크를 이용한 침수감지용 광 이중센서 개발)

  • Key, Kwang-Hyun;Kim, Hyung-Pyo;Sohn, Kyung-Rak
    • Journal of Sensor Science and Technology
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    • v.19 no.3
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    • pp.184-190
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    • 2010
  • In this paper, a remote submersion warning system based on multi-mode optical fiber(MMF) sensors and a wireless sensor network(WSN) are proposed. To improve the reliability and stability of the sensors, the dual optical fiber sensors combined to the optical coupler are demonstrated. A slave zigbee as a wireless sensor module was used as a platform to monitor and record the signal from the MMF sensors and then transmits these information to a master zigbee wirelessly. The monitoring system running the $LabVIEW^{(R)}$ software was connected to the internet to support the short message service(SMS) through extensible markup language(XML) web service. No matter where the managers are, they can always receive the real-time remote-monitoring data for safety check.

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.

Optical Wireless Remote Control Using Indoor LED Lightings (LED 실내조명을 이용한 광무선 원격제어)

  • Sohn, Kyung-Rak;Sohn, Chang-Woo
    • Journal of the Korean Society of Marine Engineering
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    • v.36 no.8
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    • pp.1111-1116
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    • 2012
  • At present, indoor optical wireless communications using LED lightings has been widely studied. The combination of this technology to the low voltage powerline grid installed in each home makes an efficient method for fulfilling the premise of broadband access for home networking. In this paper, white LEDs were used for both illumination and remote-control, so that information can be broadcast within a room for control the optical wireless systems. We implemented a model car to evaluate the performance of optical wireless remote-control. The requirement for levels of illumination suitable for communication were investigated and applied to design the test-bed. In spite of limitation of line-of-sight communications, it will open up new applications to the optical wireless remote control system in an electromagnetic interference region.

A study on the Frequency Modulation-based Audio Transmission System for Short-range Underwater Optical Wireless Communications (근거리 수중 광무선 통신을 위한 주파수 변조 기반 오디오 전송 시스템 연구)

  • Kim, Yeon-Joo;Sohn, Kyung-Rak
    • Journal of the Korean Society of Marine Engineering
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    • v.36 no.1
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    • pp.166-171
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    • 2012
  • In this paper, short-range underwater wireless communication technique using visible LEDs is proposed. As an alternative to conventional acoustic system, visible LED communications show high quality and high speed data transmission characteristics. We design a frequency modulation-based optical wireless audio transmission system. The CD4046B phase-locked loop device is applied to implement the frequency modulation and demodulation. With a transmission modulation of 100 kHz, audio signal has successfully received at a transmission distance of 30 cm.

Channel Characteristics of Indoor Wireless Infrared Communication System Due to Different Transceiver Conditions

  • Peng, Chuan;Wang, Zan;Kim, Ji-Do;Pan, Jae-Kyung
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.2A
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    • pp.198-203
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    • 2008
  • In this paper, we consider the diffuse type of indoor wireless optical communication (WOC) system. To find the channel characteristics of indoor wireless infrared communication system, we investigate the simulation process to get the impulse response of diffuse type and analyze the scenario of the indoor structure which we have built. The simulation results of the impulse response include power ratio and time delay due to bounce times. We get and discuss the receiving power distribution according to six configurations which have different transmitter and receiver positions and reflection coefficients of the indoor structure assumed. The results of this paper are useful to design the indoor wireless optical communication systems.