Cicada: A Highly-Precise Easy-Embedded and Omni-Directional Indoor Location Sensing System

For supporting location-aware computing in indoor environments, the location sensing/positioning system not only need to provide objects’ precise location, but also should own such characteristics as: isotropy and convenience for portability. In this paper, we present an indoor location sensing system, Cicada. This System is based on the TDOA (time difference of arrival) between Radiofrequency and ultrasound to estimate distance, and adopts a technology integrating Slide Window Filter (SWF) and Extended Kalman Filter (EKF) to calculate location. Consequently, it not only can determine the coordinate location within 5cm average deviation either for static objects or for mobile objects, but also owns a nearly omni-directional working area. Moreover, it is able to run independently, mini and light so that it is very easy to be portable and even embedded into people’s paraphernalia.