Research On Indoor Positioning Technology Based On Visible Light Communication

In recent years,the demand for Location Based Services(LBS)has been increasing rapidly,which has promoted the development of various wireless positioning technologies,and indoor positioning is one of the important parts of LBS.The rapid popularity of LED has provided a good infrastructure for the development of Visible Light Communication(VLC).Indoor positioning technology using VLC has received extensive attention and research in recent years due to its advantages such as high accuracy and low cost.The visible light indoor positioning algorithm based on Received Signal Strength(RSS)is currently the most commonly used algorithm,and it can usually achieve centimeter level positioning accuracy in an ideal indoor environment.However,in the real environment,the signal received by the receiving end usually has a reflected signal,and this part of the reflected signal will affect the positioning effect of the RSS positioning algorithm,resulting in a large positioning error.This thesis focuses on the performance optimization of indoor positioning using VLC in consideration of reflected power.The main research contents are as follows:1.In the indoor environment where multipath reflection exists,a positioning algorithm based on intensity combination and distance weighting is proposed.First,Kalman filtering is used to remove noise,and the influence of the factors other than reflected power on positioning performance is eliminated as much as possible.After that,the algorithm groups the received power and calculates the coordinates and weights of each group.Finally,the coordinates of each group are integrated.Weighted calculation to get the final estimated coordinates of the point to be located.The simulation results show that compared with the traditional RSS positioning algorithm,the algorithm proposed in this thesis reduces the average error of the room from 0.42 m to 0.25 m,and decreases the average error from 0.58 m to 0.35 m in the edge area that is significantly affected by the reflected power.The largest error value decreased from1.4m to 0.81 m.2.In the indoor environment where multipath reflection exists,a positioning optimization algorithm based on Inverse Vector Backoff is proposed.The algorithm further optimizes the calculated estimated coordinates,by analyzes the influence of thereflected power on the positioning process and establishing a position relationship between the estimated coordinate points and the real coordinate points.Then the inverse vector model is established between the estimated coordinates and LEDs,and finally the coordinate back movement is performed.The simulation results show that when the algorithm is executed on the coordinates obtained by the algorithm proposed in Chapter 3,compared with the traditional RSS positioning algorithm,the average room positioning error is reduced from 0.42 m to 0.17 m,which effectively reduces the indoor positioning error.