Efficient Beam‐Training Technique for Millimeter‐Wave Cellular Communications

In this paper, a beam ID preamble (BIDP) technique, where the beam ID is transmitted in the physical layer, is proposed for efficient beam training in millimeter-wave (mmWave) cellular communication systems. In order to facilitate beam ID detection in a multicell environment with multiple beams, the BIDP is designed such that the beam ID is mapped onto a Zadoff–Chu sequence in association with its cell ID. By analyzing the correlation property of the BIDP, it is shown that multiple beams can be transmitted simultaneously with the proposed technique with minimal interbeam interference in a multicell environment, where beams have different time delays due to propagation delay or multipath channel delay. Through simulation with the spatial channel model (SCM), it is shown that the best beam pairs can be found with a significantly reduced processing time of beam training in the proposed technique.