Experimental Investigation of AoA Estimation and Antenna Calibration With 5G NR SignalsUsing USRP Devices

The advent of 5G technology has significantly advanced the capability of centimeter-level positioning, with Angle of Arrival (AoA) estimation emerging as a key technique to achieve this level of accuracy. This paper presents a software receiver based on Universal Software Radio Peripheral (USRP) devices, designed for precise AoA estimation using 5G New Radio (NR) signals, specially in challenging environments. The proposed receiver addresses critical issues such as hardware and antenna calibration, synchronization, and signal processing, enabling accurate angle estimation in both outdoor and indoor environments. The study explores the impact of hardware imperfections, antenna errors and environmental factors, including multipath propagation, on angle estimation accuracy. Our approach combines AoA estimation with calibration techniques, demonstrating the feasibility of delivering reliable, high-precision location-based services with 5G signals. Through a combination of simulation and real-world experiments, we assess the performance of the system in scenarios with and without multipath interference, including the influence of reflectors on AoA measurements. The results provide a valuable foundation for advancing the understanding and implementation of precise AoA estimation and calibration using 5G NR signals and USRP devices.