Research Of Visible Light Indoor Positioning Technology

At present, outdoor positioning technology based on Global Positioning System (GPS) has been already quite mature.The success of the development of application based on outdoor positioning stimulates the development and research of indoor positioning technology. However, GPS cannot be used in the indoor positioning. The reason is that the satellite signal for GPS systems is very weak. Therefore, we need a new method for indoor positioning system without GPS system.This paper presents a research of VLC indoor positioning and has three main priorities. First, a new channel modeling was made. Second, based on this model and combining the physical properties of photoelectric sensor, the existing variety of localization algorithm was simulated. Third, a VLC indoor positioning system was designed. After comparison and study, the existing localization algorithm was improved to make the receiver keep high localization accuracy in the case of vertical displacement and tilt.In the first research point, we established a new VLC channel model based on the Lambert model. The existing channel models were established based on the ideal environment, namely the relative distance of receiver and sender remained the same and the plane of the receiver remained horizontal. This paper established a new channel model in the situation of reciever’s vertical displacement and tilt, more in line with the actual situation.In the second research point, we improved the existing ID location algorithm. Traditional ID localization algorithm has high ability of anti-interference but the precision is poor. In this paper, we made weighted average of the LEDs light intensity on the basis of the traditional ID location algorithm. Due to the use of the relative strength of LEDs, the system could keep high localization accuraty although there were tiny changes or interference on the receiver. In the third research point, a VLC indoor positioning system was designed, including the sending and receiving hardware, time-division multiplexing access and communication protocol. Through the simulation, each module worked well and laid the foundation of the implementation of the VLC indoor positioning system.