Application of LED lighting technology: analysis of visible light communication technology

Introduction: visible light is the human eye can perceive the part of the electromagnetic spectrum, visible spectrum without precise range; electromagnetic waves generally people's eyes can perceive the wavelength between 400 to 700 nm, but there are some people can perceive the wavelength in the electromagnetic wave between about 380 to 780 nm. It is generally believed that the wavelength range of visible light is between 350 and 770 nm. Visible light communication technology (Visible Light Communication, VLC), is the use of fluorescent lamps or light-emitting diodes, such as the issue of the naked eye is difficult to distinguish the high speed light and dark change light signal to transmit information. In simple terms, is the light communication.

We Chinese Semiconductor Research Institute of visible light communication research has accumulated good technology, carried out in 2008 semiconductor lighting information network based on visible light communication in the hospital under the leadership instruction (S2LINK) study, two exhibition research results at the 2010 Shanghai World Expo "Chinese Aviation Museum" and "eco home" exhibition by the Ministry of science and technology science and Technology Expo advanced collective "and" Technology Expo "advanced individual award.

In 2011, the United States Time to visible light communication technology of "LiFi" in the world's 50 largest invention in eighth based on 2012; visible light communication light "strange routing" based on the selected CCTV2 "global innovation and technology new list TOP10.

The excitement of Baer's invention of the optical wireless telephone and his expectations for the optical wireless telephone can be perceived by the wireless communication of the light that there has been a need for applications. However, the long history of the development of the telephone technology, the final choice of the wireless communications, this should be Baer did not expect. Nowadays, with the development of semiconductor lighting engineering and the development of semiconductor technology, we feel that the visible light communication technology ushered in the spring of his development.

I personally think that the application of visible light communication technology is divided into three parts, the first piece of application is the wireless electromagnetic sensitive areas (such as: aircraft, hospital, coal mine, key units, military electromagnetic environment in silence, the power of wireless communication technology can not be used, no line communication light has irreplaceable); second is the original lighting network based on low cost to increase communication function (populated areas such as: subway stations, shopping malls, conference room); third block is a creative application of visible light communication technology (light positioning, identification, self powered communication...).

The application of VLC technology will be detonated by a genius of Alexander. Graham Baer. Product designers who had invented the telephone will be visible light great inventor crossing over from 1880 to express his admiration, today all the researchers engaged in research of VLC technology will also thank, industry will cheer the era of wealth creation myth finally here! "From" the future of LED communications, "science and Technology Review (IEEE Chinese version of the Spectrum) 2003 9

Personal summary visible light communication and radio communication comparative advantage, referred to as Chen three advantages:

1, single point high rate. As of 2014, visible light communication, off-line processing the highest peak rate is the Italy team with red green and blue yellow color LED, created by WDM technology and DMT technology based on 5.6Gbps; visible light communication type LED fluorescent single real-time transmission is the highest rate of own Chinese Academy of semiconductor team using fluorescent LED. Expand the technology to create 500Mbps or 550Mbps through bandwidth. Compared with the wireless communication technology based on radio frequency signal, the speed advantage of the wireless optical communication technology based on visible light has been shown.

2, the system capacity. In order to realize broadband wireless communication with large capacity, the future development direction of wireless base station is to improve the reusability of the cell. Because the light of spatial multiplexing than spatial multiplexing is better than light electricity, to establish wireless RF wireless area smaller, so can provide high-speed real-time communication for the single user, realize the wireless optical network system of ultra large capacity optical communication through wireless area network many very small.

3, the use of very reassuring. Visible light communication signals visible and easy to control, depending on the lens and can flexibly control the lamp signal coverage area, effectively prevent information leakage, but also through visual observation signal coverage area, no longer worried about "third ears", can give users a hitherto unknown psychological sense of security. Communications security in the future will cause greater concern.