XJTLUIndoorLoc: A New Fingerprinting Database for Indoor Localization and Trajectory Estimation Based on Wi-Fi RSS and Geomagnetic Field

Abstract--In this paper, we present a new location fingerprinting database comprised of Wi-Fi received signal strength (RSS) and geomagnetic field intensity measured with multiple devices at a multi-floor building in Xi'an Jiatong-Liverpool University, Suzhou, China. We also provide preliminary results of localization and trajectory estimation based on convolutional neural network (CNN) and long short-term memory (LSTM) network with this database. For localization, we map RSS data for a reference point to an image-like, two-dimensional array and then apply CNN which is popular in image and video analysis and recognition. For trajectory estimation, we use a modified random way point model to efficiently generate continuous step traces imitating human walking and train a stacked twolayer LSTM network with the generated data to remember the changing pattern of geomagnetic field intensity against (x, y) coordinates. Experimental results demonstrate the usefulness of our new database and the feasibility of the CNN and LSTMbased localization and trajectory estimation with the database. Index Terms--Indoor localization, trajectory estimation, received signal strength, Wi-Fi fingerprinting, deep learning, CNN, LSTM, geomagnetic field. With the increasing demands for location-aware services and proliferation of smart phones with embedded highprecision sensors, indoor localization has attracted lots of attention from the research community. Global navigation satellite system (GNSS) like global positioning system (GPS), which provides accurate geo-spatial positioning, cannot be used indoors as the radio signals from satellites is easily blocked in an indoor environment.