Research On 3D Localization Technology In Indoor Environment

With the rapid development of wireless communication technology,there is an increasing demand for location-based services,especially indoor location services.In indoor environments,GPS can not work normally because satellite signals can not penetrate through the buildings,and there may be reflections,refractions,and multipath effects so on.For wireless signals,they are more complex than outdoor environments.The research on indoor localization technology has become a hot topic in the current research field.With the continuous expansion of the application field of indoor positioning technologies,the two-dimensional positioning technology can no longer meet the needs of accurate positioning in many scenarios,which requires the support of three-dimensional positioning technology.Therefore,the research on indoor three-dimensional positioning has more practical significance and application prospect.The main work and innovation of this paper are as follows.Firstly,a new three-dimensional indoor localization algorithm based on RSSI(Received Signal Strength Indication)is proposed,and it can effectively improve the localization accuracy in the case of low complexity.The estimation of non-line of sight error of each node is calculated,and then the corrected measurement distances can be obtained,which converts the non-line of sight problem into line of sight problem.The linear least squares method is used to calculate the position coordinates of the target node.Secondly,a new NLOS error mitigation algorithm for 3D indoor localization is proposed.The proposed algorithm utilizes both RSSI localization and TOA(Time of Arrival)localization.The corrected measurement distance of each node in the three-dimensional space is obtained,then the confidence factors of the information are calculated.The estimated coordinate of the target nodes can be obtained.Simulation results show that the algorithm can significantly reduce the localization error.Thirdly,in the actual verification work,a three-dimensional indoor localization system based on bluetooth was built.The iBeacon devices are used for signal transmission,and the handheld intelligent terminal is used to display the localization result in real time.The WeChat public platform and wireless signal transmission model are utilized to complete the development of the indoor three-dimensional positioning system.