A Novel Framework to Reduce the Initial Access Latency by Utilizing Multi Resolution Angle of Arrival Estimation in 6G

In the 5G New Radio (NR) millimeter(mm) wave hybrid beamforming based antenna systems, the number of simultaneous beams limited by the number of Radio Frequency (RF) chains (also limits simultaneous Angle of Arrival (AoA) estimation of signals coming from multiple directions). The Base Station (BS) can identify antenna beams for each user equipment (UE) through appropriate channel measurements. However, this process is very time consuming since BS with limited number of simultaneous antenna beams has to examine a large number of beam directions (or AoA) due to the narrow beams employed to enhance the beam searching capability. Through this manuscript we propose a novel idea to enable simultaneous AoA estimation of signals coming from different directions for a single RF chain. This technique helps to bypass transmit beam sweeping procedure, by which the UE initial access latency to find the transmit beam reduces by approximately 7 times compared to legacy systems, and this improves the Key Performance Indices.