3-Dimension Wlan-Based Indoor Localization Technology For Mobile Device

GPS (Global Positioning System) can provide real-time, all-weather and global position service. It is widely used in the result of high accuracy and easy to use. But GPS is restricted in the indoor localization. And the indoor localization technology has become the hot research spot.In this paper, it analyzes the research status of indoor localization including existing systems, their advantages and disadvantages and the tracking technology. In some research basis, one indoor three dimension localization and tracking method is proposed in this paper. And finally verify the feasibility and accuracy of this method by simulation.The method proposed in this paper is based on the WLAN (Wireless Local Area Networks) technology. It includes three steps. First, construct the channel fading model for each AP (access point) in the localization environment. Second, measure the distance. Based on the last position, verify the channel fading model to be used and then computing the distance between the point and the AP by processing the RSSI (Received Signal Strength Indication). Third, estimate the position through the distance. Last step, use the kalman filter to track the trajectory in order to improve the accuracy.At last, we simulate the method in a virtual localization environment. The result shows that this method is not only feasible but also low system cost.