Research On Array Dynamic Receiving Technology In Visible Light Communication

At present,the Industrial Internet of Things has emerged with a new round of global technological revolution and industrial transformation,involving all links and subjects of information and communication technologies such as industry and the Internet.In order to meet the needs of industrial Io T for high-speed,high-density,and low-latency communication,visible light communication provides a new type of solution.However,the movement of equipment in the industrial Internet of Things scene and the inter-cell interference caused by high-density cells pose a huge challenge to the high-speed and robust transmission of visible light communication.For this reason,this article faces the demand of visible light mobile communication for robust reception,and studies several key technologies of array visible light communication mobile reception.The main research work is specifically introduced as follows:Aiming at the problem that the receiver's field of view angle constraints and movement seriously affect the robustness of the visible light communication system,the optimal rotation angle of the receiver is optimized,and the random distribution function of the channel capacity difference is derived.First,with maximizing the channel capacity as the optimization goal,the optimal design criterion for the optimal rotation angle of the receiver in a single LED scene is constructed.The optimization criterion is that the rotation angle does not exceed the boundary of the receiver's field of view as the constraint condition,and the Kuhn-Tucker condition and the second-order sufficient condition are used as the optimization method to obtain the optimal solution.The optimization results illustrate the mechanism of the optimal rotation angle receiver overcoming the viewing angle constraint.Construct the channel capacity difference model between the best rotation angle receiver and the vertical upward receiver,and derive the cumulative distribution function and probability density function of the channel capacity difference when the receiver moves following a random distribution.The research results have guiding significance for analyzing the best receiving model of the receiver in the mobile scene.Aiming at the inter-cell interference between adjacent LEDs in the one-dimensional corridor VLC system,the rotating receiver is optimized to suppress inter-cell interference,and the random distribution function of the signal-to-interference-to-noise ratio and the average bit error rate are derived.When the receiver moves to the overlapping area of adjacent cells,the inter-cell interference becomes the main factor restricting the system performance,so the best rotation angle receiver is used to suppress the inter-cell interference.To maximize the signalto-interference and noise ratio as the optimization goal,the optimal design criteria for the optimal rotation angle in the one-dimensional corridor dual-cell scenario are constructed.The optimization criterion takes the rotation angle not exceeding the receiver's field of view as the constraint condition,and takes the Kuhn-Tucker condition and the second-order sufficient condition as the optimization method to obtain the best rotation angle.The best rotation angle receiver effectively suppresses inter-cell interference,making thermal noise the main factor that affects the receiver's signal-to-interference and noise ratio.According to the random distribution of receiver movement,the probability density function and cumulative distribution function of the signal-to-interferenceto-noise ratio are derived to obtain the average bit error rate of the best rotation angle receiver.The results show that in the visible light communication system of one-dimensional corridor,the performance of the best rotation angle receiver is affected by the random distribution type of receiver movement and the cell spacing.Aiming at the inter-cell interference in the indoor visible light communication system,with the signal-to-interference-noise ratio as the optimization target,the structural parameters of the aperture array receiver are designed and optimized in the two modes of directional reception and ergodic reception.The aperture array receiver consists of a bare central detector and multiple receiving units,and uses an avalanche photodiode as the detector.Because the amplification gain of the avalanche photodiode makes the inter-cell interference the main factor affecting the system,the maximum signal-to-interference-to-noise ratio is taken as the optimization goal,and the parameter optimization criterion of the aperture array receiver is constructed.The optimal structural parameters of the aperture array receiver are optimized for the two receiving modes of the receiver in the indoor center position and the traversal indoor position.Among them,the parameters received by the receiver at the indoor center position are optimized to obtain an analytical solution,and the receiver traverses the parameter optimization of the indoor position to obtain a simulation solution.The results show that the optimized aperture array receiver is better than a single avalanche photodiode and general angular diversity receiver.