CMBF-based dynamic selection for heterogeneous massive MIMO systems

In this paper, an optimal coordinated multipoint beamforming (CMBF) scheme is proposed for heterogeneous networks (HetNets) with massive multiple input multiple output (MIMO) systems for energy efficiency (EE), taking into account the maximum transmission power of the base station (BS) with the limitation on the power consumption of the static circuit. This paper analyzes the influence of the different parameters on the EE and derives a closed-form expression. We investigate the different cooperation schemes, considering the influence of the number of antennas of small base station (SBS) and macro base station (MBS), the quality of service (QoS), and the number of different service users. Therefore, the best parameters can be selected for optimizing EE with the different scenarios in HetNets with massive MIMO systems. Theoretical derivation and simulations show that the amount of BS antennas, achievable rate constraints, quantity of service users, and cooperative schemes all have the vital influences on the EE for the CMBF design. Therefore, the proposed optimization framework enables us to identify key system parameters, and obtain the better system design for the massive MIMO HetNets.