白光LED照明的可见光通信的现状及发展

用室内照明的白光LED光源作为通信基站进行信息无线传输的技术是当前国外光无线通信领域的研究热点之一,是一项有发展前景的新兴技术.文章详细介绍了白光LED照明的室内可见光通信技术在国内外的研究现状,分析了其关键技术,阐述了其发展趋势.     

基于白光LED的可见光通信技术研究

可见光通信是基于白光LED的新兴无线光通信技术,能够同时实现照明和通信的双重功能,适合在智能家居等领域的应用。本文对基于白光LED的室内可见光通信的研究现状及关键技术、发展趋势进行了研究。     

基于可见光通信的矿灯身份识别系统

煤矿井下矿灯普遍采用绿色能源、低功耗的固态(LED)作为发光光源,因此利用白光LED可见光通信为井下无线通信提供了一个新方法。文中基于矿灯设计了一种可见光身份识别系统。该识别系统包括识别卡和读卡器,并采用开关按键(OOK)调制技术和自编码通信协议结构,实现了身份识别信息通信。该系统具有照明、通信以及便携等优点,在煤矿井下矿灯考勤中具有一定的实用价值。     

白光LED室内可见光通信的关键技术

可见光通信是一项新兴基于白光LED的无线光通信技术,具有发射功率高、不占用无线电频谱、无电磁干扰、无电磁辐射和节约能源等优点,能够同时实现照明和通信的双重功能。阐述了可见光通信技术的发展动态,介绍基于白光LED的室内可见光通信系统,并对提高系统整体性能的若干关键技术进行了研究讨论,为白光LED室内可见光通信系统进一步研究提供依据。     

基于白光LED的可见光通信研究进展

白光LED将成为未来主要的照明光源,这使得基于白光LED的可见光通信(VLC)在通信网络中具有一定的优势。介绍了可见光通信系统的优势及发展概况,分析了包括通信速率的提高、全双工通信的实现以及与现有通信网络互联等关键技术,综述了可见光通信技术的应用现状,并展望了可见光通信技术的应用前景。     

基于白光LED的可见光通信研究进展

白光LED将成为未来主要的照明光源, 这使得基于白光LED的可见光通信(VLC)在通信网络中具有一定的优势。介绍了可见光通信系统的优势及发展概况, 分析了包括通信速率的提高、全双工通信的实现以及与现有通信网络互联等关键技术, 综述了可见光通信技术的应用现状, 并展望了可见光通信技术的应用前景。     

白光LED室内可见光通信的关键技术

可见光通信是一项新兴基于白光LED的无线光通信技术,具有发射功率高、不占用无线电频谱、无电磁干扰、无电磁辐射和节约能源等优点,能够同时实现照明和通信的双重功能.阐述了可见光通信技术的发展动态,介绍基于白光LED的室内可见光通信系统,并对提高系统整体性能的若干关键技术进行了研究讨论,为白光LED室内可见光通信系统进一步研究提供依据.     

用于提升可见光通信调制带宽的微尺寸LED性能研究

基于白光发光二极管(LED)的可见光通信、照明两用系统近年来得到广泛的研究,然而普通LED性能制约了可见光通信调制带宽.为进一步提高LED的调制带宽,可采用微尺寸LED.简要阐述了提高LED调制带宽的方法,综述了近年来在优化可见光通信调制带宽的微尺寸LED性能方面的进展,指出了未来微尺寸LED的研究方向.     

基于室内可见光的通信系统性能优化分析

阐述可见光通信特点,基于发光二极管为核心的新型无线光通信技术。探讨影响白光LED传输性能的因素,白光LED传输性能的关键技术,从而提升白光LED传输性能。     

室内可见光通信APD 探测电路的设计与实现

室内可见光无线通信技术是随着白光LED 照明技术的发展而兴起的无线光通信技术。在分析目前的可见光通信技术基础上,针对室内可见光通信系统的应用需求,设计了雪崩光电二极管(APD)探测电路组件。首先阐述了APD 探测电路的工作原理,其次详细设计并分析了系统各组成部分的电路结构及其功能,最后对所设计的用于室内可见光通信接收子系统的探测组件进行了相关实验测试。实验结果表明:设计有效可行,APD 探测电路具有增益高、带宽宽、温控可靠、稳定性好等优点,对室内可见光通信系统有很好的应用价值,为室内可见光通信系统进一步研究提供依据。     

基于白光LED的可见光通信系统及其实现

研究基于LED新型环保光源,利用OptiSystem软件搭建了一套可见光通信系统,并通过仿真对其进行性能分析,使得可见光系统在提供照明功能的同时,还可以把信号调制到LED可见光光束上进行数据传输,从而实现安全性更高、数据率更高的白光LED可见光通信。     

基于MIMO的可见光通信系统研究

可见光通信是利用LED发出的可见光传输信息的,可见光通信兼顾照明和通信,同时LED具备发光强度高、耗能低、无电磁干扰,有着巨大的发展潜力。文章指出,将MIMO技术应用于可见光通信系统,合理地对LED进行布局,可提升系统的可靠性。同时文章研究了可见光通信系统中的调制技术,比较了几种常见的调制技术,分析了各自的优缺点。     

室内可见光通信光功率分布的实验研究

室内可见光通信技术是基于白光LED（发光二极管）照明光源的无线光通信技术,在机场、医院等严格限制电磁干扰的场合可替代射频通信,应用前景广阔。鉴于室内可见光在传输过程中墙壁反射引起的多径效应对信号传输质量的影响,本文在4.0m×4.0m×2.8m的房间内测量了室内可见光系统光源的光功率分布,结果表明光源的光信号经墙壁反射,会造成严重的多径效应,从而产生码间干扰。本文对室内可见光功率分布的仿真研究进行了实验验证,实验结果与理论仿真研究基本吻合。     

A Study of Shadowing on Indoor Visible-Light Wireless Communication Utilizing Plural White LED Lightings

White LED is considered as a strong candidate for the future lighting technology. We have proposed an optical wireless communication system that employs white LEDs for indoor wireless networks. In this system, LED is used not only as a lighting device, but also as a communication device. The transmitter has large optical power and large emission characteristics to function as lighting device. And the system has specific wireless channel impulse response differing from infrared wireless communication. In this paper, we discuss about shadowing effect on the system utilizing plural LED lightings including the performance of ISI based on the impulse response. We consider the downlink transmission based on TDMA and evaluate the shadowing effect caused by pedestrians with computer simulation. When the shadowing often occurs at 800 Mb/s, the performance of outage call duration rate and blocking rate are improved by using 3 LED lightings compared with 1 or 2 LED lightings. And, we show that the system with the optimal number of the LED lighting is robust against shadowing and can accommodate more calls. Toshihiko Komine was born in Shizuoka, Japan, on November 17, 1978. He received the B.E. and M.E. degrees in Information and Computer Science from Keio University, Yokohama, Japan, in 2001 and 2003 respectively. He is currently studying for the Ph.D. degree at Department of Information and Computer Science, Keio University. His current research interests are optical wireless communications and LED communications. Shinichiro Haruyama is a professor at Department of Information and Computer Science, Faculty of Science and Technology, Keio University, Yokohama, Japan. He received an M.S. in engineering science from University of California at Berkeley in 1983 and a Ph.D. in computer science from the University of Texas at Austin in 1990. He worked for Bell Laboratories of AT{&}T and Lucent Technologies, U.S.A from 1991 to 1996, and for Sony Computer Science Laboratories, Inc. from 1998 to 2002. His research interests include reconfigurable system, system design automation, wireless communication, and visible light communication. Masao Nakagawa was born in Tokyo, Japan in 1946. He received the B.E., M.E. and Ph.D. degrees in electrical engineering from Keio University, Yokohama, Japan, in 1969, 1971 and 1974 respectively. Since 1973, he has been with the Department of Electrical Engineering, Keio University, where he is now a Professor. His research interests are in CDMA, consumer Communications, Mobile communications, ITS (Intelligent Transport Systems), Wireless Home Networks, and Visible light Communication. He received 1989 IEEE Consumer Electronics Society Paper Award, 1999-Fall Best Paper Award in IEEE VTC, IEICE Achievement Award in 2000, IEICE Fellow Award in 2001. He was the executive committee chairman on International Symposium on Spread Spectrum Techniques and Applications in 1992 and the technical program committee chairman of ISITA (International Symposium on Spread Spectrum Techniques and Applications) in 1994. He is an editor of Wireless Personal Communications and was a guest editor of the special issues on “CDMA Networks I, II, III and IV” published in IEEE JSAC in 1994 (I and II) and 1996 (III and IV). He chairs the Wireless Home Link sub-committee in MMAC (Multimedia Mobile Access Communication Promotion Committee).     

Line of sight model for visible light communication using Lambertian radiation pattern of LED

This paper illustrates line of sight model for visible light source and a photodiode in wireless communication. Light‐emitting diodes (LEDs) are predominantly used everywhere like in houses and factories as light source due to development in technology of light sources. Haitz's law predicts an exponential rise in light output and efficiency of LEDs over a period of time. Light‐emitting diodes are having an average life of 50 000 hours with efficiency of 140 lm/W. Light‐emitting diode light sources are used for an eco‐friendly world due to its advantages over conventional wireless communication systems. For communication purpose in the visible light range, the LED and photodiode are used. A visible light communication system with LED as the transmitter and photodiode as the receiver is simulated in MATLAB for line of sight and analyzed using a Lambertian radiation pattern with a different mode number, field of view, and half power angle.     

基于PWM的可见光通信系统设计

为了解决传统可见光通信技术中抗光干扰能力弱的问题,采用脉冲宽度调制(PWM)的调制方式,以STM32为核心处理器,完成了可见光通信系统的设计.实验中将两颗50 ix光通量的LED光源发出的可见光作为信息载体,在室内非封闭空间的0.5m直视链路上,在9 600 Bd的单工通信下,误差仅为1.879 0×10-4.实验结果表明,基于PWM调制的可见光通信系统能降低室内光线干扰的问题,将促进可见光通信技术在室内无线通信领域的发展和应用.     

Advances and prospects in visible light communications

Visible light communication (VLC) is an emerging technology in optical wireless communication (OWC) that has attracted worldwide research in recent years. VLC can combine communication and illumination together, which could be applied in many application scenarios such as visible light communication local area networks (VLANs), indoor localization, and intelligent lighting. In recent years, pioneering and significant work have been made in the field of VLC. In this paper, an overview of the recent progress in VLC is presented. We also demonstrate our recent experiment results including bidirectional 100 Mbit/s VLAN or Li-Fi system based on OOK modulation without blue filter. The VLC systems that we proposed are good solutions for high-speed VLC application systems with low-cost and low-complexity. VLC technology shows a bright future due to its inherent advantages, shortage of RF spectra and ever increasing popularity of white LEDs.