The Design And Implementation Of The Wireless Communication Transmission And Receiving Link Based On Visible Light

Due to the advantages of light-emitting diode‘s(LED)high energy efficiency,durability,and low cost,they are widely used in the market,using LEDs for the applications of optical modulation data communication has led to extensive research.At the same time,because the optical channel can provide several THz bandwidths,Visible light communication(VLC)is expected to coexist with traditional radio frequency(RF)communications in the future as a reliable solution to the demand for high-speed wireless communications.At present,the research focus of VLC is on short distance and high data rate transmission,but there is a lack of practical research on civil and industrial application scenarios.One of the main factors is the lack of universality and easy upgraded visible light communication platform.Because of this situation,this paper designs a softwaredefined visible light communication(SDVLC)transceiver link based on the idea of software defined radio(SDR).The research content mainly includes the following points:1.The electrical characteristics of high-power LEDs and PIN photodiodes are studied as the basis for the design of analog transceiver functional modules;Based on the visible light line-of-sight channel model,the optical path transmission characteristics are analyzed by simulation and used as the basis for optical path design.2.According to the electrical characteristics of LEDs and PINs,an analog transceiver link suitable for high-power,high-bandwidth,and linear optical signal transmission is designed and implemented.Among them,the high-power LED linear drive circuit and the linear photoelectric receiving circuit complete the basic optical transceiver function in optical communication;The LC filter circuit in the link has the characteristics of high roll-off and low loss,and realizes a manual production and measurement method for n H-level precision radio frequency inductance in the filter circuit;the bridge T equalization and linear amplification module circuit realized in the link can be used for analog equalization,which can effectively compensate the channel bandwidth and signal power after the transmission of the visible light analog link.3.This paper designed a digital platform based on Zynq and high-performance dual-channel 14bit×250MSPS analog to digital converter(ADC)and 16bit×500MSPS digital to analog converter(DAC),which realized software-defined and flexibly configured digital functions,and the key points,difficulties,and solutions of the design are described in detail.4.In this paper,a test platform was built to effectively test the system link,and verified the performance of each module,realize the stable file transfer function at a distance of 10 m.The software-defined visible light transceiver link designed and implemented in this project has the advantages of controllable cost,stable operation,strong practicability,easy maintenance,and upgrading,which provides an effective reference plan for the practical promotion and application of visible light communication.