  The paper presents a comparison of performance of two Kalman Filters:
extended Kalman filter (EKF) and unscented Kalman filter (UKF) in a hybrid
Bluetooth-Low-Energy-ultra-wideband (BLE-UWB) based localization system. In the
system, the user is localized primarily based on Received Signal Strength (RSS)
measurements of BLE signals. The UWB part of the system is periodically used to
improve localization accuracy by supplying the algorithm with measured UWB
packets time difference of arrival (TDOA). The proposed scheme was
experimentally validated using two algorithms: the EKF and the UKF. The
localization accuracy of both algorithms is compared.
