Is Centimeter Accuracy Achievable for LTE-CSI Fingerprint-Based Indoor Positioning?

Channel state information (CSI) fingerprint based indoor positioning has been extensively studied. While centimeter-level positioning accuracy has been demonstrated for Wi-Fi systems, only meter-level accuracy was reported for Long-term Evolution (LTE) systems. To investigate whether the centimeter accuracy is achievable or not for LTE systems, we examine the factors that affect the positioning accuracy to guide the implementation of a LTE-CSI fingerprinting system, where a novel phase compensation method is proposed to improve the CSI quality. We demonstrate for the first time that the centimeter-level positioning accuracy is achievable for LTE systems through extensive experiments.