Research On The Architecture And Performance Optimization Of The Visible Light Networking

Visible Light Communication(VLC)has become a hot topic of research at home and abroad because it can make up for the lack of spectrum resources and can fulfill the needs of lighting and communication at the same time.Currently,VLC has matured into point-to-point communication technology,and considerable results have been achieved.To meet the needs of users for high data transmission in indoor networks,this paper proposes the application of VLC,a communication technology that supports high speed,to the networking technology to ease the pressure on indoor networks.For the VLC networking system,which is still in the initial stage of research,there are problems with resource allocation,such as the dynamic demand for service rate by users in the network and the dynamic change of channel quality due to user mobility.How to allocate network resources reasonably according to the current user status is a problem that must be solved.The existing resource allocation methods have been hindered by high complexity such as the resource allocation method for RF/VLC heterogeneous networks,and such methods are also inconvenient to apply in sensitive environments such as substations and other electromagnetically sensitive areas for practical applications.To solve those above problems,this paper focuses on two aspects of the VLC network dynamic resource allocation algorithm and relay-based VLC network resource allocation algorithm to address the above problems.(1)Most of the current VLC network resource allocation methods focus on power allocation and subcarrier allocation,and such methods have bottlenecks in hardware facilities in practical applications,and cannot effectively meet the dynamic change of channel quality and dynamic service requirements in indoor VLC networks.To address these problems,this paper designs a VLC network resource allocation algorithm based on real-time channel quality and service demand,and dynamic time slot allocation.Based on the fixed time slot allocation TDMA,this paper dynamically changes the time slot allocation length according to the different channel quality and service requirements of users,which not only enables all users to communicate at the required minimum service rate,but also enables it to achieve two resource allocation strategies of ensuring user Qo S and maximizing throughput in the presence of different requirements of network users.The algorithm proposed in this paper achieves a maximum 67% throughput improvement compared to the fixed time slot resource allocation method.The dynamic resource allocation algorithm proposed in this section can lay the foundation for subsequent research on VLC network relaying methods.(2)Most of the relaying techniques currently used to extend the coverage of VLC networks are heterogeneous networks with RF technologies,which have high complexity of information integration and are inconvenient to deploy in electromagnetically sensitive environments.To solve this problem,this paper proposes a VLC network relay algorithm: based on the D-TDMA allocation algorithm proposed above,this paper dynamically plans the relay link path after obtaining the link information of users.In this way,the relaying algorithm in this paper allocates time slot resources to all users on-demand,realizing a rational use of bandwidth resources.And its simulation verifies that the throughput of near-end users is improved by up to 49% and that of far-end users is improved by 64%,greatly improving the quality of service for far-end users.