Research On Technologies Of Indoor Visible Light Communication Based On White Light LED

The abnormal growth of mobile data service leads to the over-utilization of radio frequency(RF)spectrum,which makes it overcrowded.Visible light communications(VLC)takes advantage of low-cost and solid-state lighting devices such as light-emitting diode(LED)to realize that multiplexing wireless communication while lighting or displaying.And it expands the spectrum resources of wireless communication and is expected to become a new technology for 6G generation mobile networks.With the improvement of white light LED manufacturing technology and luminous quality,white light LED is widely used in the field of indoor lighting.With the huge interactive demand in the Internet of things project in the 5G era,the popularization of LED makes the indoor visible light communication for lighting and communication multiplexing have great potential in the application of the Internet of things.Therefore,indoor visible light communication may become a breakthrough in the application and popularization of visible light communication technology.This thesis studied the indoor visible light communication technology based on fluorescent white light LED.By establishing the indoor visible light communication model,the spatial distribution of light source and photodetector(PD)of indoor VLC system was optimized.The multipath effect of MIMO-VLC technology and the influence of PD position on transmission strategy were analyzed.Through analyzing the shortcomings of the classical distribution model of indoor visible light communication,three kinds of lighting and communication multiplexing models with high power LED were established,which make the illumination and signal power distribution of whole receiving plane more uniform,and effectively improve the signal-to-noise ratio and optimize the bit error rate,and the applicable scenarios of the three models are analyzed.The models were simulated based on MIMO-VLC technology.The channel impulse responses were analysed,and the channel characteristics of models and the MIMO transmission strategies for different detector positions were given.By analyzing the distribution of root mean square delay spread(RMSDS)in the wholeroom,the highest data transmission rates of the three models under OOK modulation were obtained.Based on the matrix theory method,this thesis analysed the channel states of three models under the specific deployment of detectors,and the relationship between photodetector spacing and channel state.The MIMO transmission strategies under the specific deployment of detectors were given,which overcame the adverse effect of multipath effect on communication effect.Moreover,an intelligent family system of indoor visible light communication based on white light LED communication and lighting multiplexing was built in this thesis.The Ethernet signal is converted into optical control signal by using super network port and OOK modulation.Optical control operations over 80% success rate of controlled equipment such as television,air conditioner,microwave oven and oven were realized through Web pages.