[Back]

H. Hofer, G. Retscher:
"Combined Wi-Fi and Inertial Navigation with Smart Phones in Out- and Indoor Environments";
Talk: VTC2017-Spring Conference, Sydney, Australien (invited); 2017-07-04 - 2017-07-07; in: "VTC2017-Spring Conference", (2017), 978-1-5090-5932-4/17; 5 pages.

For positioning with Wi-Fi of a mobile user usually location fingerprinting is employed. This approach consists of two phases, i.e. a training and a positioning phase. In the first one the received signal strengths RSSs of the surrounding Access Points APs are measured on reference points RPs with known coordinates. In the second phase a user measures the RSS and estimates his current location using a matching approach with the RSSs measured on the RPs. To achieve acceptable positioning results training measurements on a large number of RPs in a high density must be carried out. The aim of the novel approach presented here is to reduce this labour consuming process by using an intelligent selection of RPs without degrading positioning accuracies. These selected RPs are termed intelligent check points iCPs and are well distinguishable waypoints which have to be passed along when navigating from a start point to the desired destination. Thus, these iCPs define the trajectory in a logical manner. With extensive field campaigns in combined out- and indoor environments it is proven that a significant reduction of the required time for training by a factor of 4 to 5 is achieved as well as the positioning accuracies are increased to 2.0 m on average. Moreover, continuous user localization is achieved by using an integration of inertial navigation with the absolute positioning capability from Wi-Fi fingerprinting.

location fingerprinting, Wi-Fi, training phase, intelligent check points, inertial sensors, sensor fusion