The Study Of Wifi-based Fingerprinting Location System

With the increasing improvement of people’s requirement of the service based on location,various positioning techniques play a more and more important role in our personal and social life,as well as the industrial production area.Compared with other location technology,Received Signal Strength(RSS) based positioning in wireless local area network(WLAN) has been more widely recognized with its lower requirements for the hardware devices and higher positon precision.First of all,by the comparision among the most prevalent and widely used indoor position systems and techniques from two aspects:the situation of its current researh and the principle of its location,the thesis reveals the superiority of RSS based positioning in WLAN compared with other positioning techniques.Then we present a necessary analysis of the two phases of its whole working process,which includes a discussion of how to ensure the sampling datas’effectiveness during offline stage and a brief introduction of the key online positioning algorithms.Secondly,this paper puts forwards the WiFi fingerprinting location system based on the experiment type.Due to the powerful data processing and simulation analysis of Matlab,which present us with a clear display of the offline fingerprinting construction process, location feature extraction and analysis is completed;And also we realize the simulation analysis of the WiFi continuous location system’s time average algorithm.Later, the paper introduce the method to identify floor in WiFi fingerprinting location system.The method can be divided into two steps:floor distinction and floor’s change-detection. Only if a floor’s change-detection has been successfully completed,the floor distinction will work.So the success of floor’s change-detection is what really matters.Compared with measuring the pressure with a special device,utilizing the MEMS of smart-terminals is proposed for floor’s change-detection,simply because it can be highly adapt to different situations.In the end,we put the method to identify floor in WiFi fingerprinting location system into our experiment environment,and compared the accuracy of the location system using the method with the one without using it,which reveals the effectiveness of our proposing method’s contribution to the improvement of the system’s location precision.