Coordinated Multicell Beamforming Based on Power Minimization in an Uplink–Downlink Configured Massive MIMO Network

In this paper, the coordinated beamforming problem is investigated to minimize the sum transmit power of the system in a two-cell network, downlink transmission in one cell and uplink transmission in the other cell. It is assumed that the base stations (BSs) and the users are equipped with multiple input multiple output (MIMO) antennas, and the coordinated beamforming vectors are designed for the BS in the downlink cell and the users in the uplink cell under the signal-to-interference plus noise ratio (SINR) constraints. Then, the problem is extended for a scenario where the BSs and users have massive MIMO antennas, and using the random matrix theory, an algorithm is proposed to design the coordinated beamforming vectors. Simulation results show that this coordinated beamforming algorithm for the massive MIMO scenario accurately tracks the optimal sum transmit power minimization beamforming approach, while it reduces the computational complexity of the coordinated beamforming.