LED조명을 이용한 수중환경에서의 VLC 연구

정희석(Hui-Sok Jung),양연모(Yeon-Mo Yang),허경무(Kyung Moo Huh) 大韓電子工學會 2011 電子工學會論文誌-SC (System and control) Vol.48 No.5

LED(Light Emitting Diode) 소자는 현대 기술의 발달로 형광등이나 전구보다 수명이 길고 전력소모가 작으며 제어가 쉽다는 장점을 가지고 있다. 이러한 이유로 LED 소자를 이용한 조명이 많이 사용되고 있다. 최근 LED 소자의 고속응답특성을 이용한 통신기법인 가시광통신(Visible Light Communication, 이하 VLC)이 주목받기 시작하였다. VLC의 경우 전파를 사용하지 않아 주파수 할당이 필요가 없으며, 데이터전송에 ISM(Industrial Scientific Medical band)과 같은 간섭 또한 존재하지 않는다. 그렇기 때문에 VLC에 관한 연구 결과가 많이 나오고 있다. 본 논문에서는 기존의 LED 조명을 사용한 VLC와 수중환경에서의 VLC에 대한 survey를 진행하고 활용방법을 살펴보았다. LED(Light Emitting Diode) components have advantages of longer lifetime, lower power consumption and easy-to-control, compare to normal lamp and fluorescent light, according to the development of recent technologies. Thus, lots of illuminations which utilize LED components could be used. Recently, Visible Light Communication(VLC) which is a part of communication technologies, utilizing high speed response characteristic of LED components, started receiving public attention. In case of VLC, there is no need of frequency allocation due to no use of radio, but also no interference exists during data transmission, much different in ISM((Industrial Scientific Medical band). This is the reason why a lot of research results about VLC are becoming issued. In this paper, a survey of feasibility for using VLC utilizing an original LED illumination for underwater applications has been done and a primitive possibility of its application has been examined.

가시광 통신용 변조방식에 따른 성능비교

김우종(Woo-Jong Kim),이효진(Hyo-Jin Lee),김명환(Myeng-Hwan Kim),김선형(Sun-Hyoung Kim) 한국정보기술학회 2012 Proceedings of KIIT Conference Vol.2012 No.11

본 논문에서는 조명으로 사용되는 LED(Light Emitting Diode)를 이용하여 가시광 통신 시스템으로 통신이 가능할 뿐만 아니라 효율적인 통신을 위한 변조 방식에 대한 연구를 수행하였다. 가시광 통신은 LED 조명의 특징인 고속 스위칭을 이용하여 가시광 통신 시스템에 적용한다. 기존의 가시광 통신 시스템은 주로 OOK(On-Off-Keying) 변조를 이용한다. 하지만 본 논문에서는 여러 가지 변조 기법을 적용하여 가시광통신 시스템에 효과적으로 사용 될 수 있는 변조기법을 LabView를 이용한 시뮬레이션을 통해 선별하였다. 실험결과 FSK(Freguency Shift Keying) 변조가 가장 가시광 통신 시스템에 적합한 통신임을 입증할 수 있었다. In this paper, we study the modulation scheme for efficient communication, as well as the visible light communication system using LED(Light Emitting Diode) lighting. Visible light communication using LED lighting features high-speed switching system was applied. Conventional visible light communication systems mainly use OOK (On-Off-Keying) modulation. However, in this paper, various modulation techniques were sifted through the modulation schemes to see which technique can be used most effectively in the visible light communication system simulation using LabView. The experimental results demonstrated that the FSK(Freguency Shift Keying) technique is the most suitable for visible light communication systems.

LED를 이용한 가시광 통신 시스템에서 2-step 인터리빙을 통한 BER 성능 향상

이종현,서효덕,한두희,이계산,이규진 한국위성정보통신학회 2015 한국위성정보통신학회논문지 Vol.10 No.2

Visible Light Communication (VLC)은 Light Emitting Diode (LED)를 사용하여 조명의 역할과 통신의 기능을 동시에 구현할 수 있는 효과적인 방법이다. VLC는 통신 가능 영역인 Field Of View (FOV)를 가져 높은 보안성을 가지고, 가시광을 이용해 고속의 데이터 전송이 가능하다. VLC 시스템에서 RGB 채널에 데이터를 분할하여 전송하는 방법은, RGB 채널에 동일한 데이터를 전송하는 방법에 비해 빠른 데이터 전송 속도를 가지고 있으나, 가시광의 산란 및 반사로 인한 데이터의 burst 에러가 발생할 시 복원이 불가 능하여 BER 성능의 열화가 발생한다는 단점이 존재한다. 이러한 문제를 해결하기 위해 VLC에서 빠른 데이터 전송률을 가지면서 BER 성능 향상을 만족하는 2-step 인터리빙 기법을 제안한다. 제안 시스템의 Cyclic 인터리빙과 convolutional 인터리빙을 통해 RGB 채널의 성능 평준화 및 데이터 에러율의 감소로 전체 시스템의 BER 성능이 향상됨을 확인 할 수 있다. Visible Light Communication (VLC) is effective way to realize the light device and communication device using a Light Emitting Diode (LED) simultaneously. VLC has high security for Field Of View (FOV) communication area, also which is possible to transmit the high data rate using visible light. In VLC, transmitting the divided data by the RGB channels is higher data rate than transmitting the same data by RGB channels. However, it occurred the burst error by scattering and reflection of visible light which is impossible to restore that. To solve the problem, we proposed the 2-step interleaving scheme that high data rate and improve the performance of BER in VLC. The proposed system implements cyclic interleaving and convolutional interleaving that is able to be standardized the performance of RGB channels and improve the performance of BER using error correction.

디지털 도어락 시스템을 위한 파일럿 기반 신호검출 성능

이선의,황유민,선영규,윤성훈,김진영,Lee, Sun Yui,Hwang, Yu Min,Sun, Young Ghyu,Yoon, Sung Hoon,Kim, Jin Young 한국전기전자학회 2018 전기전자학회논문지 Vol.22 No.3

본 논문은 VLC (Visible Light Communication)의 새로운 응용 분야인 IoT 도어락 시스템을 위한 신호검출 방법을 제안한다. 보안성에 대한 이슈로 새로운 기술에 대한 수요가 있는 도어락 시스템에 VLC를 적용하기 위해서 극복해야 되는 사용자 인식을 위한 신호 검출 기법에 대해 설명한다. 이 시스템은 기존 인프라를 사용하여 가시광으로 통신을 수행하기 때문에 보안 및 높은 신호 검출 특성을 가진 것을 보인다. FFT를 사용한 신호 검출을 위하여 파일럿 신호를 기반으로 인증 채널에 접근한 사용자의 신호를 검출하고 이에 따른 채널 모델에서 오경보 확률과 검출 확률의 성능을 보인다. This paper proposes a signal detection method for IoT door lock system which is a new application field of VLC (Visible Light Communication). This paper describes the signal detection technique for user recognition that needs to be overcome in order to apply VLC to door lock system which has a demand for new technology due to security issue. This system has security and high signal detection characteristics because it uses existing infrastructure to communicate with visible light. In order to detect the signal using FFT, the signal of the user who accesses the authentication channel based on the pilot signal is detected, and the performance of the false alarm probability and detection probability is shown in the channel model.

조명 LED 통신을 위한 변조방식에 관한 연구

이효진(Hyo-Jin Lee),김우종(Woo-Jong Kim),김선형(Sun-Hyoung Kim) 한국정보기술학회 2013 Proceedings of KIIT Conference Vol.2013 No.5

본 논문에서는 조명으로 사용되는 LED(Light Emitting Diode)를 이용하여 가시광 통신 시스템으로 통신이 가능할 뿐만 아니라, 기존의 PD(Photo Diode)와의 통신이 아닌 LED간의 통신 실험을 진행하였다. 기존에 사용하던 다양한 변조방식들을 시뮬레이션을 통해서 가시광통신에 적합한 변조방식을 선정하였다. 이렇게 선정한 ASK(Amplitude-Shift-Keying) 변조 시스템을 하드웨어로 구성하여 가시광 통신에 적용하여 봄으로서 LED 간의 통신에 적용하여 실험 및 측정한 결과 근거리용의 데이터통신용으로 사용이 가능함을 입증하였다. In this paper, we have conducted experiments to be able to communicate with a visible light communication system using LED(Light Emitting Diode) lighting, as well as communication without the existing PD(Photo Diode) communication between the LED. Various modulation schemes used in existing simulation were selected modulation scheme suitable for visible light communication. ASK(Amplitude-Shift-Keying) modulation system hardware components, so selected and applied to the visible light communication can be used for short-range data communication of the results of experiments and measurements in the communication between the LED as spring proved.

Dimmable Spatial Intensity Modulation for Visible-light Communication: Capacity Analysis and Practical Design

Kim, Byung Wook,Jung, Sung-Yoon Optical Society of Korea 2018 Current Optics and Photonics Vol.2 No.6

Multiple LED arrays can be utilized in visible-light communication (VLC) to improve communication efficiency, while maintaining smart illumination functionality through dimming control. This paper proposes a modulation scheme called "Spatial Intensity Modulation" (SIM), where the effective number of turned-on LEDs is employed for data modulation and dimming control in VLC systems. Unlike the conventional pulse-amplitude modulation (PAM), symbol intensity levels are not determined by the amplitude levels of a VLC signal from each LED, but by counting the number of turned-on LEDs, illuminating with a single amplitude level. Because the intensity of a SIM symbol and the target dimming level are determined solely in the spatial domain, the problems of conventional PAM-based VLC and related MIMO VLC schemes, such as unstable dimming control, non uniform illumination functionality, and burdens of channel prediction, can be solved. By varying the number and formation of turned-on LEDs around the target dimming level in time, the proposed SIM scheme guarantees homogeneous illumination over a target area. An analysis of the dimming capacity, which is the achievable communication rate under the target dimming level in VLC, is provided by deriving the turn-on probability to maximize the entropy of the SIM-based VLC system. In addition, a practical design of dimmable SIM scheme applying the multilevel inverse source coding (MISC) method is proposed. The simulation results under a range of parameters provide baseline data to verify the performance of the proposed dimmable SIM scheme and applications in real systems.

플리커 방지를 위한 바이트반전 가시광통신 시스템에서 조명 제어 방법

이성호 ( Seong-ho Lee ) 한국센서학회 2018 센서학회지 Vol.27 No.3

In this paper, we introduce a new dimming control method in a visible light communication (VLC) system wherein byteinversion is adopted for flicker-free transmission. In the VLC transmitter, the original and the inverted data were sent sequentially and the remnant time in one period was used for the dimming control of the LED light. In the VLC receiver, only the original data was recovered using the gating signal whose width was the same as the length of the original data. In our experiments, the dimming control ranges were measured to be 22%-53%, 11%-76%, and 5%-88% of the CW LED light when the data rates were 9.6, 19.2, and 38.4 kbps, respectively. In this system, we used a 240-Hz sync pulse whose period was 4.16 ms, which was shorter than the maximum flickering time period of 5 ms that is generally considered to be safe. This configuration is very simple and useful in constructing indoor wireless sensor networks using the flicker-free LED lamps with dimming control capability.

A survey of design and implementation for optical camera communication

Le, N.T.,Hossain, M.,Jang, Y.M. Elsevier 2017 SIGNAL PROCESSING-IMAGE COMMUNICATION - Vol.53 No.-

<P>Visible Light Communication (VLC) has emerged as a promising technology for wireless communication owing to advantages such as bandwidth, license, coexistence and security. Additionally, it was officially standardized by IEEE 802.15.7 in 2011. However, it faces certain challenges that can be considered as grounds to develop a revised version. Optical camera communication (OCC) operates in the same channel band as VLC with more advantages on receiver characteristic and is a candidate for the standardization of issues in IEEE 802.15.7r1. Specifically, OCC presents a new and inexpensive technology that is different from other technologies such as radio frequency technology. Its advantages include the usage of built-in cameras in smart devices that can act as receivers for OCC. Existing lighting systems, such as light-emitting diodes (LEDs), liquid-crystal displays (LCDs), and digital signage, can operate as transmitters. This study provides an overview of extant research on the design and implementation of OCC. The analyses and discussions in the survey present relevant fields of implementation and future directions for OCC technology.</P>

LED Deployment for improving Received Optical Power Distribution in Visible Light Communication Systems

Muhammad Tabish Niaz,Fatima Imdad,Hyung Seok Kim 대한전자공학회 2015 ITC-CSCC :International Technical Conference on Ci Vol.2015 No.6

Wireless technology is paving its way to the next generation of communication system: 5G. As the radio spectrum is exhausted, the need for the use of free unlicensed frequency band is increasing. One of the possible solutions is to use visible light communication (VLC) for indoor applications. VLC utilizes light emitting diodes (LED) for providing illumination and data communication. Hence for VLC to work for high data rate and mobile applications, there is a need to maintain a steady received optical power distribution (ROPD) over the reference receiving plane. To tackle this issue the placement of LEDs with in the room plays an important part. This paper proposes circular LED deployment technique to improve the ROPD at the receiving plane.

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

최수일 한국광학회 2012 Current Optics and Photonics Vol.16 No.3

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.