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Searching and Autoalignment Method for Indoor Free-space Optical Communication

실내용 자유 공간 광 통신을 위한 수신단의 위치 탐색 및 자동 링크 정렬 방법

  • Lee, Kwanyong (LiDAR and Intelligent Optical Node (LION) Laboratory, Department of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST)) ;
  • Cho, Seung-Rae (LG Digital Park High UHD Project) ;
  • Lee, Chang-Hee (LiDAR and Intelligent Optical Node (LION) Laboratory, Department of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST))
  • 이관용 (카이스트 전기 및 전자공학부) ;
  • 조승래 (LG 디지털 파크 High UHD Project) ;
  • 이창희 (카이스트 전기 및 전자공학부)
  • Received : 2019.09.30
  • Accepted : 2019.11.07
  • Published : 2019.12.25

Abstract

We propose and demonstrate a searching and autoalignment method for indoor optical wireless communication, using a cost-effective retroreflective sheet and a microelectromechanical system (MEMS) mirror. We use an extremum-seeking method for a single axis and beam steering with a MEMS mirror to maintain a line of sight (LOS) with the optical link. This autoalignment method shows a receiver sensitivity of -31.87 dBm for a bit rate of 2.5 Gb/s over a 7 m communication link.

저렴한 retro-반사지와 미소 전자 기계 시스템(micro electro-mechanical system, MEMS) 거울을 이용한 실내용 무선 광 통신용 위치 탐색 및 자동 링크 정렬 방법을 제안하고 실험하였다. 직접적인 가시선(line of sight, LOS) 확보를 위하여 retro-반사지에서 돌아온 빛으로부터 수신단 위치를 파악하고 MEMS 거울을 통한 빔 조종으로 통신 링크를 자동 정렬하였다. 자동 정렬된 광 링크를 통하여 7 m 전송 거리에서 2.5 Gb/s NRZ 신호를 전송하여 비트 에러율 10-12에서 수신 감도 -31.87 dBm의 성능을 가졌다.

Keywords

References

  1. Ericsson, "Mobile data traffic growth outlook," (Ericsson Mobility Report, November 2018), https://www.ericsson.com/en/mobility-report/reports/november-2018/mobile-data-traffic-growth-outlook.
  2. J. M. Kahn and J. R. Barry, "Wireless infrared communications," Proc. IEEE 85, 265-298 (1997). https://doi.org/10.1109/5.554222
  3. A. Gomez, C. Quintana, G. Faulkner, and D. O'Brien, "Challenges in wide coverage indoor optical communications using fibre-wireless-fibre links for terabit data rates," in Proc. IEEE Globecom Workshops (USA, San Diego, Dec. 2015), pp. 1-5.
  4. A. Gomez, K. Shi, C. Quintana, G. Faulkner, B. C. Thomsen, and D. O'Brien, "A 50 Gb/s transparent indoor optical wireless communication link with an integrated localization and tracking system," J. Lightwave Technol. 34, 2510-2517 (2016). https://doi.org/10.1109/JLT.2016.2542158
  5. P. Brandl, A. Weiss, and H. Zimmermann, "Automated alignment system for optical wireless communication systems using image recognition," Opt. Lett. 39, 4045-4048 (2014). https://doi.org/10.1364/OL.39.004045
  6. S. Jeon and H. Toshiyoshi, "A bi-directional free-space optical communication system with MEMS spatial light modulator for agile data link," in Proc. 2017 IEEE 30th International Conference on Micro Electro Mechanical Systems (MEMS) (USA, Las Vegas, Jan. 2017), pp. 297-300.
  7. H. G. Kraus, "Huygens-Fresnel-Kirchhoff wave-front diffraction formulation: paraxial and exact Gaussian laser beams," J. Opt. Soc. Am. A 7, 47-65 (1990). https://doi.org/10.1364/JOSAA.7.000047
  8. M. Krstic and H. H. Wang, "Stability of extremum seeking feedback for general nonlinear dynamic systems," Automatica 36, 595-601 (2000). https://doi.org/10.1016/S0005-1098(99)00183-1
  9. A. Virtuani, E. Lotter, and M. Powalla, "Influence of the light source on the low-irradiance performance of $Cu(In,Ga)Se_2$ solar cells," Sol. Energy Mater. Sol. Cells 90, 2141-2149 (2006). https://doi.org/10.1016/j.solmat.2005.01.022