Channel Characteristics Of Visible Light Communication Under Indoor Scenario

Visible light communication technology was mainly used to transmit information through brightness changes of LED(Light-Emitting Diode)lamps.LED could be used for both illumination and communication,which had attracted a lot of attentions because of its rich spectrum resources,safe,no electromagnetic and some other advantages.In recent years,visible light communication technology was developing rapidly.With the rapid popularization of LED applications,visible light communication has great development potential in the future.As a new communications technology,there were still some issues to be resolved for visible light communication technology.In this paper,we focused on the problems of short distance of visible light communication,strong signal attenuation when the line of sight was blocked and the uneven distribution of indoor signal power.Then the antenna distribution of transmission side and the FOV of receiving side were analyzed,the optimized FOV value and distribution structure were obtained.Meanwhile,the performance reliability of indoor visible light communication was evaluated when line of sight were blocked,then we designed a multi-antenna coordination mechanism to achieve communication under dynamic indoor environment.Details are as follows:(1)We established the system model of indoor visible light communication,then the basic model of the system?impulse response and noise of system were analyzed.The optimized LED array distribution scheme was selected through comparative analysis the communication performance of different LED distribution structures.(2)Proceed from received optical power and received SNR for single scene model,the relationship between the system performance and the FOV value was analyzed,and the optimized FOV range to meet no blind area was obtained.(3)We created indoor multi-scene occlusion models,then the communication performance was evaluated through the distribution of indoor reception SNR,noise and other interference factors under Shading Scenario.Meanwhile,to solve the problem of communication links can be easily interrupt by occlusion under practical scenarios,we designed a dynamic cooperative communication system and method,which could help to monitor the change condition of links and maintain constant communication even the state of links under full occlusion.