Phase-based Angle estimation approach in Indoor Localization system using Bluetooth Low Energy

As the demand for a highly accurate indoor positioning system (IPS) increases, the selection of technology and methodology becomes a critical aspect by making it an active area for the researchers. Several techniques are already in the competition to provide an accurate, power-efficient, and low-cost system such as Wireless Fidelity (Wi-Fi). In this paper, we present a phase-based angle measurement approach for calculating the angle using Bluetooth Low Energy (BLE). Bluetooth Low Energy, or colloquially BLE also known as “Bluetooth SMART,” promises an improved accuracy and low power requirement for its operation. The proposed BLE direction-finding approach introduces a phase-based method to measure the angle, i.e., Angle of Arrival (AOA). Herein, the estimation locator listened for the Constant Tone Extension (CTE) packet and measured the In- Quadrature (IQ) samples based on which the angle calculation has been performed. The experimental results show a mean error of 1.9
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in the indoor environment.