Research On Multi-user Access Technology In Visible Light Networking

With the commercialization of the fifth generation(5G)wireless system,the gradual rise of new services and the large-scale growth of terminals,higher bandwidth requirements have prompted forward-looking research to focus on the future sixth-generation communication network technology and the exploration of new spectrum resources.Researchers are increasingly concerned about the definition and further development of 6G as the successor of 5G.Visible light communication has become one of the subversive supplementary technologies for 6G networks due to its advantages such as no need to apply for spectrum resources,low price,green environmental protection,anti-electromagnetic interference,and large bandwidth.However,its optical characteristics are obviously different from radio frequency wireless technology.The physical layer channel characteristics limit the upper-layer networking mechanism.It is impossible to realize full-duplex multi-user networking at visible light level.Therefore,the network must be studied based on the characteristics of the special channel of visible light Mechanism.In view of this,the specific research content and results of this article are as follows:(1)In this paper,from the perspective of multiple access based on time slot,as the method basis of multi-user access research in visible light networking,a terminal-oriented central coordinated resource reservation multiple access scheme is proposed for bi-directional multi-user VLC system.Improve user access speed through automatic user discovery and registration;Centralized coordination is adopted to reduce system complexity and user access interaction.Dynamic management of access user resources to improve the bandwidth efficiency of visible light link to ensure no information collision during data frame transmission(2)A multi-user simulation platform based on bi-directional visible light link is built,and three special system parameters N₁?N₂ and z are introduced to achieve the balance between system throughput and access delay,and meet the application requirements of 6G for extremely high throughput and ultra-low delay.(3)A network prototype system is built to verify the above theoretical research content.Experiments show that by designing appropriate system parameters,the system performance can be easily changed,and the visible light multi-user access can be well realized.The scheme has the advantages of resource reservation,low complexity,balanced performance and cost-effectiveness.