Abstract
This paper presents an acoustic indoor localization system for commercial smart phones that emit high pitched acoustic signals beyond the audible range. The acoustic signals with an identifier code modulated on the signal are detected by self-built receivers which are placed at the ceiling or on walls in a room. The receivers are connected in a Wi-Fi network, such that they synchronize their clocks and exchange the time differences of arrival (TDoA) of the received chirps. The location of the smart phone is calculated by TDoA multilateration. The precise time measuring of sound enables high precision localization in indoor areas. Our approach enables applications that require high accuracy, such as finding products in a supermarket or guiding blind people through complicated buildings. We have evaluated our system in real-world experiments using different algorithms for calibration-free localization and different types of sound signals. The adaptive GOGO-CFAR threshold enables a detection of 48% of the chirp pulses even at a distance of 30 m. In addition, we have compared the trajectory of a pedestrian carrying a smart phone to reference positions of an optic system. Consequently, the localization error is observed to be less than 30 cm.
Highlights
From the sustained rise and ubiquitous availability of mobile computers, smart phones, and handheld devices in everyday life, a multitude of exciting new location-dependent applications have emerged
The GPS-Module in commercial off-the-shelf (COTS) smart phones and hand-held devices makes navigation systems reliable to assist in outdoor areas [1]
We use a chirp impulse to increase the performance of the system by using pulse compression
Summary
From the sustained rise and ubiquitous availability of mobile computers, smart phones, and handheld devices in everyday life, a multitude of exciting new location-dependent applications have emerged. The demand for navigation in large structures as railway stations, airports, trade fair halls, or department stores is obvious, since the equipment, the mobile device of the people, is already available. The GPS-Module in commercial off-the-shelf (COTS) smart phones and hand-held devices makes navigation systems reliable to assist in outdoor areas [1]. There is the need for new localization approaches, since the reliability of GPS vanishes in densely built-up urban areas and is completely void inside buildings. To effectively navigate people in their environments, for example, to specific products in a supermarket or to particular exhibition booths on trade fairs, a more accurate localization system as GPS is needed. For indoor applications alternative technologies are required to provide the signal inside buildings with a low cost infrastructure
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: International Journal of Navigation and Observation
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
