Optimal Design Of Angle Diversity Receiver And Intelligent Reflecting Surface For Indoor Visible Light Communication

With the development of wireless communication technology,visible light communication(VLC)has been widely concerned by scholars due to its advantages of fast transmission rate,high security and confidentiality,no spectrum application,no electromagnetic interference and low cost.VLC is a communication method that modulates the transmitted signal to light emitting diode(LED),and transmits information by using the high-speed light and dark flashing signal sent by LED.It could communicate while taking into account lighting.Diversity Receiver technology is one of the research focus in VLC field.Angle diversity receiver(ADR)could provide better system performance compared with single detector receiver.In addition,intelligent reflecting surface(IRS)is also a research focus in the field of wireless communication,which has pronounced effects on improving communication flexibility,enriching communication forms,and improving communication quality.Therefore,the angle diversity receiver and intelligent reflecting surface have been studied in this paper.The specific contents of the work are as follows:(1)In indoor visible light communication system,the optical power on the receiving plane is an important index that would affect the performance of indoor VLC system.When single detector receiver is used,the center region of indoor receiving plane obtains higher optical power while the edge region gets lower optical power.The uneven distribution of the received optical power would affect the fairness of indoor communication.In order to solve this problem,an angle diversity receiver has been proposed to improve the uniformity of optical power distribution in indoor VLC system.The effects of different diversity merging modes,different number of side detectors and inclination angle on indoor optical power distribution have been analyzed by simulation.The simulation results show that the variance of received optical power could be greatly reduced by selecting proper diversity merging mode,inclination angle and number of side detectors.Finally,the optimized optical power distribution has been obtained by using the optimal number and inclination angle,and the effect of the proposed ADR optimization structure on the uniformity of the received optical power distribution has been analyzed.(2)In order to improve the performance of the indoor VLC system,an IRS and ADR-assisted indoor VLC system model has been established in this paper.The yaw angle and roll angle of IRS have been regarded as variables to model the signal to noise ratio maximization problem of the indoor VLC receiving plane.Then,the bat algorithm has been adopted to solve the problem.Furthermore,IRS with optimal yaw angle and roll angle and ADR with optimized structure have been applied to assist the indoor VLC system simultaneously.The performances of the original,IRS and IRS and ADR-assisted VLC systems have been studied by simulation.The results show that compared with the original VLC system,the indoor VLC system with IRS has some advantages in the performances such as signal-tonoise ratio,transmission rate and bit error rate.Further,the performance of IRS and ADRassisted indoor VLC system has been improved significantly.This work could provide some reference for designing and implementing high-performance VLC system.