A study of localization methods on mobile platform and WiFi-based user movement detection
University of Delaware
Modern smartphones can provide various features to enrich people's everyday life. Localization is one feature that has gained more popularity recently. The fundamental techniques to support localization are GPS, WiFi and Cell-ID. Each technique is different from another in terms of accuracy, energy consumption and availability. Although GPS, WiFi and Cell-ID come in handy for localization on mobile phones, there are still some problems that limit their usage, such as low battery capacity and the high cost to locate a user indoors. Therefore, some new positioning systems are required to improve the performance of localization. In this paper, the main positioning techniques(GPS, WiFi, Cell-ID) along with their advantages and disadvantages are introduced. Several existing positioning systems are then presented. Users' mobility is also very useful for positioning systems. One common idea is to use a user's mobility to control when to turn on/off the location sensing mechanism. For example, it is not necessary to track a user when he is standing still so the location sensing mechanism should be turned off in this case. In addition to the localization, I suggest two WiFi-based movement detection methods, Majority agreement and Top K, in this paper. The evaluation shows that both methods are able to provide approximately 90% accuracy to distinguish between absolute standing still and moving at walking speed around the UD area.