Hybrid Beamforming for Distributed Communication Systems in Internet of Things

In recent years, with the continuous development of positioning technology, the location information of Internet of Things users (IOT) can be easily obtained. Distributed commu-nication is a key technology in the Internet of Things. In this paper, we associate IoT users with remote antenna units (RAUs) by obtaining bidirectional location information of receivers and base stations, and construct a beamforming matrix based on the bidirectional location information of users and RAUs for receiver distribution. Hybrid beamforming algorithm for communication. Specifically, we first associate RAUs with IoT users, and each user is associated with only one RAU. Next, we divide beamforming into two steps. In the simulated beamforming stage, the codebook-based beamforming vector is determined synchronously according to the angular parameters of the main path. In the digital beamforming stage, the digital beamforming matrix is based on the principle of maximizing spectral efficiency (MSE). Simulation results show that the algorithm complexity is reduced from
$\mathbf{O}(N^{4})$
to
$\mathbf{O}(N^{3})$
in the user association stage, and is greatly reduced in the beamforming stage.