The Research On WLAN-based Indoor Localization System

Driven by the rapid development of mobile smart devices, the need for obtaining position information timely and accurately is more and more urgent. However, the location technologies as GPS which has high positioning accuracy cannot be applied to the indoor environment. It is necessary for indoor location to seek its own solution.In this paper, we choose the widely used Wi-Fi as the platform of indoor position, use received signal strength(RSS) which is easily collected as the information of location,and design an improved matching algorithm for Fingerprint Location.This thesis firstly reviews and discussed the existing indoor positioning systems and techniques.. Then the principles and characteristics of the relevant technology are introduced and analyzed. The RSSI data that collected in the actual position area is used to study the path loss caused by walls and walking people. Improve the Location-based indoor positioning method, then design and implement the whole position system. The main contents and results of the research in this paper are as follows:Firstly, we analysis the characteristics of wireless radio signal in the complex indoor environment as the basis for position. The RSSI data that collected in the actual position area is used to study the path loss caused by walls and walking people.Secondly, this paper design an improved indoor location system based on Fingerprint localization. Fingerprint localization is divided into two stages: off-line stage and on-line stage. During the off-line stage, we build the database and devide regions. During the on-line stage, we compare the received signal with database and obtain the coordinate. This paper applies smooth algorithm in the offline phase and proposes a weighted distance algorithm based on improved KNN for matching in the online phase.Then, a fingerprint-based WLAN indoor positioning system is designed in this paper. The software development environment of the localization system is introduced,the overall architecture and each functional modules of the system is designed. After the design of the system architecture, all the functions of the positioning system are implemented by the programming language JAVA.Finally, the system test is done in the experimental environment, including the offline database creation and the online positioning test to ensure the normal operation of each module.The position accuracy of the before improved is compared with thatof the after improved,and the effect of K value on the results.