Research And Implementation Of Visible Light Illumination And Communication System Based On PoE

Traditional indoor lighting fixtures usually use incandescent lamps,fluorescent lamps and other light sources,and are generally manually controlled lighting methods.Due to stroboscopic flicker,low intelligence and energy waste problems,they cannot meet peoples intelligent and diverse lighting needs.At present,light-emitting diodes have developed into the main lighting due to high luminous efficiency and long life.Lighting fixtures are the most widely distributed electromechanical equipment and are excellent carriers for the Internet of Things.The combination of power over ethernet and lighting fixtures will provide low-voltage direct current for lighting fixtures,and can solve the problems of resource waste and management decentralized in traditional lighting,and have ability to transmit high-speed information.6G communication is coming soon,and digitalization and intelligence have become the only way under the wave of new technologies.LED intelligent lighting combined with visible light communication will bring new values in smart classrooms,intelligent transportation,and promote the sustainable development of society.This thesis mainly realizes the PoE-based visible light lighting communication system:（1）Firstly,the research progress of PoE intelligent lighting technology and VLC technology are thoroughly investigated,and the technical challenges are pointed out.The dilemma is that it fails to fulfill the increasing demands for higher quality life in Io T era;Secondly,the technical solution of PoE intelligent lighting and the electro-optical characteristics of LEDs are analyzed,and the key performance evaluation indicators affecting indoor lighting are introduced,such as light intensity,blue light hazard,color rendering index;Finally,the relationship between volt-ampere characteristics,P-I characteristics and modulation bandwidth of LEDs and visible light communication performance are analyzed,it laid foundation for the realization of PoE-based intelligent lighting communication system.（2）Aiming at the existing problems of high color rendering index and low blue light hazard in existing lighting fixtures,serious resource waste,and low intelligence,a distributed PoE intelligent lighting sensor system design scheme is proposed.Firstly,adopt the golden light and white LED mixed light strategy,according to the CIE 1931standard,dimming model of light chromaticity parameters and pulse width modulation is established,the dynamic fuzzy neural network is used to optimize the design of the model.Secondly,the device selection and circuit design of the PoE intelligent lighting system are introduced.Using the Io T and integrating the intelligent sensor controller,the brightness and color temperature can be adjusted in real time to achieve on-demand lighting.Finally,tested and analyzed the actual lighting performance of PoE smart lighting fixtures,compared with traditional lighting pattern,this system has more advantages:low blue light hazard（RG0）,high color rendering index（85-95Ra）,continuously adjustable color temperature（2000K-6000K）,no flicker and uniform illumination.It can reduce energy consumption,meet the lighting needs in real life,and boost healthy lighting and low-carbon energy conservation.（3）Aiming at the VLC system problems in large-scale Io T connection,such as low integration,small communication rate and modulation bandwidth,the optimization design and communication performance analysis of VLC system based on PoE intelligent lighting are carried out.Firstly,the design scheme of VLC transceiver analog link based on PoE intelligent lighting system is introduced.The equalization technology is used at the transmitter to improve the modulation bandwidth.The optical design and optimization of the transmission channel uses Fresnel lenses to improve the transmission efficiency and stability.The receiving end uses PIN photodiode and low-noise transimpedance amplifier to improve the signal-to-noise ratio.The frequency response of the system was tested and verified under the conditions of communication distance of 20cm and output power of 0.1m W.The proposed equalization circuit can effectively improve the flatness of the amplitude-frequency response curve of the system,and its-3d B bandwidth is extended from 10.4MHz to more than 110MHz,which can meet the basic communication service requirements.Finally,analyze the communication performance of system,through simulation and actual measurement,it was found that the systems bit error rate can reach levels of 10^-6,indicating that the system has good communication capabilities.