| VLC has become a research hotspot due to its green and healthy,fast transmission rate,and no need for spectrum application.VLC modulates data to white LED,and transmits information by using high-speed bright and dark flashing signal sent by LED,which can provide lighting and communication functions at the same time.The LED light source layout in the VLC system affects the illuminance uniformity and communication reliability.Therefore,this thesis studies the light source layout,the PSO algorithm to optimize the light source position and power,and the impact of audio signal transmission on the VLC system.The main work completed in this thesis includes:1.The influence of LED light source layout on the illuminance and SNR distribution of the VLC system is analyzed,and a new polygonal light source layout is proposed.At 5m × 4m × 3m a rectangular room,12 LED light sources are distributed at the edge of the ceiling,and 4 LED light sources are distributed at the four corners of the ceiling,with a distance of 0.05 m from the edge of the ceiling,and 1 LED light source is distributed at the center.Compared with the traditional grid light source layout,circular light source layout and elliptical light source layout using the same number of LED light sources in the same environment,the results show that the illuminance uniformity of polygonal light source layout is 0.81,and its simulation results are better.2.A PSO algorithm is proposed to optimize the light source position and power of the polygonal light source layout.The illuminance uniformity is selected as the fitness function when optimizing the light source position.On this basis,when optimizing the light source power,the Q is selected as the fitness function,and the new model and power factor of the polygonal light source layout are obtained.The illuminance and SNR performances are simulated and compared with those before optimization.The results show that the illuminance uniformity is increased by 8.64% when the position is optimized,and the Q is increased by 61.61% when the power is optimized.A 10:1scale-down experimental system was built,and the rationality of the polygonal light source layout was verified by comparing the simulation and experimental data.3.The working principle of the indoor VLC audio transmission system is introduced in detail,and the transmission performance of the audio signal is tested in the experimental system of polygonal light source layout built in this thesis.The results show that the transmission distance of the system is 1m,the audio signal transmission effect is good,there is no distortion,and the system has a certain ability to resist ambient light noise. |
