SRS-based Wideband AoA Estimation Method in 5G New Radio

In the fifth-generation (5G) new radio (NR), angle-of-arrival (AoA) information is essential for many applications such as user tracking, positioning service, and beamforming procedures. Traditional AoA estimation methods can not be directly utilized in the commercial 5G systems due to imperfections of the hardware and multi-carrier characteristics of the 5G signals. In this paper, we exploit the wideband sounding reference signal (SRS) in the 5G for AoA estimation based on commercial devices. We first develop the method of measuring the physical SRS and calibrating the estimated channel frequency impose (CFR), then we propose a novel focusing MUSIC-like algorithm to estimate the AoA of wideband SRS. Numerical and experimental results illustrate the effectiveness of the calibration method and the focusing MUSIC-like algorithm. The accuracy of the proposed AoA algorithm can achieve 5° and 10° in 95% cases for the single-path and multi-path indoor scenarios, respectively.