Research And Implementation Of Physical Layer Transceiver In Wireless Visible Light Communication

Light is the best gift of nature for human kind.Despite its richness,light is used only for illumination.Meanwhile,current wireless communication techniques have to occupy the whole micro-wave frequency band.However,the bandwidth of visible light is about 410 THz,50000 times than the sum of current microwave communication bandwidth.This work uses visible light rather than traditional microwave radio frequency signal as signal carrier,enable safe and reliable wireless network can be used by everyone through light.The problem this thesis is trying to solve is how to establish a physical layer transceiver of visible light wireless communication system,including physical transceiver and modulation and demodulation algorithm and its physical implementation.The approaches this thesis adopt to solve the problems are:A DFTS-OFDM based method is designed to improve the baseband data modulation and demodulation algorithm;Designing a broadband optical transceiver based on LED-APD,and a hardware verification platform to verify the various links.Finally,the self-designed hardware platform achieves a 34Mbit/s physical layer data transmission rate,and is able to carry out transparent transmission of HDMI video data which has an effective data rate at 11 Mbit/s.Through the optical lens,the effective transmission distance is extended to more than 2 meters.While designing the whole architecture,the thesis also solved many significant problem,such as:methods of symbol precision synchronization of DFTS-OFDM based on the cyclic prefix and post-equalization,design of broadband TCA drivers and TIA Rx,methods of large slew rate current signal mixed grounding etc.And the thesis explored the receiver optical waveguide and optical gain method preliminarily.All of those problems are the key bottlenecks of whether the visible wireless communication can be transformed into commercial communication technology.