Research On Channel Modeling And Characteristics Of Indoor Visible Light Communication

Visible Light Communication(VLC),as a new combination of lighting and communication mode,has become one of the current research hotspots at home and abroad because it can meet the demand for higher capacity and ultra-high experience rate.The development of LED technology and the spectrum resources of visible light in the order of THz create conditions for high-speed 6G communication.As the main demand for data traffic from user terminals is slowly shifting to indoor environments,research on indoor VLC has also received extensive attention.Accurate channel modeling can better provide theoretical references for developing efficient and reliable communication systems as well as analyzing and optimizing system performance.In this paper,we focus on channel modeling in indoor environments and systematically analyze the channel-related characteristics,as well as investigate the optimization of the light source layout.The specific work is as follows:(1)In order to comprehensively understand the indoor visible light communication system and establish appropriate visible light communication channel model,we proceed to analyze and compare several common modeling methods,such as iterative method,Monte Carlo algorithm,ray tracing method,so as to explore the suitable indoor VLC channel model and modeling methods.(2)Based on the strengths of Zemax ray tracing method,the single and multiple LED arrays in indoor environment are modeled and simulated by using Zemax software and Matlab software.The simulation results are analyzed from the channel impulse response,light intensity,received light power,signal-to-noise ratio and root-mean-square time delay expansion and other channel parameters,and the impact of this channel modeling on the system channel characteristics under LOS channel and NLOS channel is further explored.(3)Since the standard whale optimization algorithm is stochastic for the initial population screening,convergence speed is slow,and it is easy to fall into local optimum,this paper uses elite backward learning to initialize the population,introduces a nonlinear convergence factor in the process of position iterative update,uses inertia weights and adaptive adjustment search strategy to further correct the population,and gives the basic steps and flow chart of the improved algorithm.Different benchmark test functions are used to compare and analyze the improved whale optimization algorithm with the standard whale optimization algorithm(WOA),the basic particle swarm algorithm(PSO)and the gravitational search algorithm(GSA)to detect the effectiveness of the algorithm.The results show that the improved whale optimization algorithm(IWOA)has higher solution accuracy and faster convergence speed.(4)Based on the improved whale optimization algorithm,the appropriate objective function is constructed to optimize the LED layout of indoor visible light communication.According to the analysis of simulation results,the optimized layout can significantly improve the illumination uniformity and received light power in the room,which provides theoretical reference for the actual LED deployment.