Adaptive TDOA Estimation for Positioning in NB-IoT

Narrowband-Internet of Things (NB-IoT) is the low power wide area (LPWA) technology developed by 3GPP for low-cost and power-efficient IoT devices. Due to the IoT requirements for efficiency, this scheme operates with limited specifications (bandwidth, sampling rate, etc.) that can limit the positioning performance based on observed time difference of arrival (OTDOA). In order to improve OTDOA-based localization performance in multipath scenarios, this paper presents an adaptive-threshold-based TDOA estimator with a previous successive interference cancellation (SIC) stage for NBIoT systems. Simulation results show that the proposed solution outperforms the classical OTDOA scheme in different multipath channels.