Evaluation of Feedback and Feedforward Coupling of Synthetic Aperture Navigation with LTE Signals

An indoor pedestrian localization system which is based on cellular long-term evolution (LTE) carrier phase measurements and synthetic aperture navigation (SAN) is developed. The proposed system relies on a moving antenna array to determine the direction-of-arrival (DOA) of received LTE signals, while suppressing multipath signals. Two schemes are studied to couple LTE carrier phase measurements with SAN: (1) feedforward LTE-SAN and (2) feedback LTE-SAN. The performance of both coupling schemes is validated experimentally in a challenging indoor environment, in which the proposed system traversed a distance of 126.8 m in 100 seconds, while receiving LTE signals from 6 eNodeBs. The position root mean-squared error (RMSE) exhibited by the proposed LTE-SAN approach was 5.20 m and 4.32 m with feedforward and feedback coupling, respectively, compared with 7.19 m using a standalone LTE approach.