Direction Finding Method for Fast Beam Alignment in Wireless Communication Systems

This paper proposes a simple direction finding (DF) method which aims to realize efficient beam management in mm-wave and THz frequency-band communications where a beamforming is essential. In the proposed method based on the DF built by the synthesis of two pre-designed beam patterns, the relative angle difference of direction-of-attention (DoA) between the beam direction formed by transmitting array antenna and the receiving antenna can be estimated. Accordingly, the receiving device having a DoA value within a specific range can be recognized as being in the main direction of a transmission beam. Also, we design the beam measurement method that is immune to implementation issues such as the imperfect frame synchronization in OFDM systems. Simulation results show the performance of angular filtering of the proposed method in the line-of-sight (LOS) environment.