A Reconfigurable Full-Digital Architecture for Angle of Arrival Estimation

In recent years, Real-Time Localization Systems (RTLS) are gaining significant attention from the scientific community. Usually, RLTS rely on positioning techniques based on the electromagnetic (e.m.) propagation properties of the received signals. Among the many possible approaches, RTLS based on the Angle-of-Arrival (AoA) estimation allows for accurate results with a comparatively lower number of receivers. In this work, we propose a novel, fully digital synchronous architecture for AoA estimation based on phase interferometry. After reviewing the state-of-the-art on full-hardware techniques for localization, the main blocks composing the proposed architecture, are discussed in detail, along with their dimensioning equations. The granularity with which the system estimates the phase shifts used to compute the AoA is reconfigurable according to the desired accuracy. The architecture is lightweight and computes the AoA in real-time. To validate the proposed approach, the RTLS architecture has been implemented on an Intel Cyclone IV E EP4CE115F29C7 FPGA board interfaced with a custom-designed receiver front-end, and experimental results on benchmark applications have been collected and analyzed.