Indoor Visible Light Positioning System Based On Particle Filtering

Indoor Visible light communication(VLC),which translates in free space and has the advantages of high transmission rate,environment friendly and excellent modulation performance,develops rapidly in recent years as a new communication technology.In general,we would align a few LEDs in the ceiling to achieve the indoor uniform illumination.However,different from the usual wireless communication,the directionality of light as the communication medium arises new challenges in keeping the connectivity between the mobile devices and light source under the mobile circumstances.The simplest method is that all LEDs broadcast data of every user simultaneously,but it wastes too much bandwidth resource,especially when the amount of users increases.If we make the difference LED transmitting the difference information,then we can realize the space division multiplexing based on the position of the LED.Through this way,the throughput of the network can be improved greatly.We call this network as indoor microcellular visible light communication network.This paper is focusing on the positioning in indoor microcellular visible light communication network and handover method between LEDs.We first analyze that the existing indoor positioning technologies has the disadvantages of high cost,complex deployment and using inconveniently.Then we explore the handover method that has being adopted in current communication system.Three creative points are included in this paper.Firstly,we propose a novel indoor positioning scheme based on Kalman filter.We analyze the feasibility,superiority and the influence factor of this scheme and describe the workflow.In the positioning process,an extra photo detector(PD)is also used to accomplish the trilateration.After that,the Kalman filter is utilized for improving the tracking performance in real time and the positioning accuracy is measured in the end.Secondly,the handover mechanism based on the position of user is proposed.We choose an arrangement model of LEDs which gets the balance between the cost and performance after analyzing a variety of layout.As the limitation of the microcellular area covered by a LED,the handover procedure may not completed timely when a user moves quickly between the LEDs.So we propose the pre-handover mechanism.This could guarantee the quality of the user's service.The simulation result shows that the handover success rate could be 97%.Last,we introduce the indoor visible light handover platform.We realized the communication and handover between multi-clients under different LEDs using UDP SOCKET and serial port command.