Research On Anti-occlusion And Anti- Interference Technology In D2D Visible Light Communication System

With the increasing demands for information sharing among mobile users, device-to-device(D2D) technology has emerged. However, this technology utilizes the limited traditional radio spectrum resources, which cannot provide the satisfied bandwidth services for users. The larger available bandwidth in visible light communication(VLC) provides attractive opportunities for D2D. Thus, this paper proposes device-to-device visible light communication(D2D-VLC) to accomplish large bandwidth transmission among mobile users. Due to the unique properties of visible light, there are some differences in the channel characteristics between the VLC and the traditional wireless communication. How to ensure the communication quality through effective technology of anti-occlusion and anti-interference still need to continuously study in the D2D-VLC system with the obstructions and interferences from the other light source.In this paper, the anti-occlusion and the anti-interference technology in D2D-VLC system are studied. By analyzing the research status of these two solutions, the paper presented the main innovation, including the following two aspects:?Propose a game theory-based mode cooperative selection mechanism for anti-occlusion.Combining the D2D technology in mobile cellular networks and the characteristics of VLC, we propose a concept of the D2D-VLC system in which include three communication modes: direct communication mode,indirect communication mode, and mixed communication mode. Moreover,this paper proposes the game theory-based mode cooperative selection mechanism to solve the problem of communication quality degradation caused by the occlusion in D2D-VLC system. Two modes of selection rules,which is based on the best-response dynamics and the best response in game theory, are included in the mechanism. In this mechanism, we use system capacity as the utility function optimized by a series of convergence algorithms to improve the system performance. The simulation and experimental results show that the cooperative mode selection mechanism has certain advantages in reliability and energy saving of the whole system,compared with the other two communication mechanism.?Propose a blind source separation-based anti-interference mechanism.Blind source separation technology is commonly used in the field of the signal processing. This technique makes it possible to separate the source signals in the case where both the source signal and the channel are unknown or randomly based on the independent component analysis. In the D2D-VLC system, we can adopt the above-mentioned technology to separate the mixed signal from the different transmitters. And then, it can eliminate other interfering signals by extracting the unique identification code assigned to the transmitters.