Massive MIMO Heterogeneous Networks: Downlink Sum Rate Maximization under Power Control

This paper studies the rate maximization problem of a heterogeneous network composed of a massive multi-input-multi-output macro base station overlaid with small cells. The rate maximization is formulated as an optimization problem that maximizes the total sum rate of all users while maintaining an acceptable quality of service per user and total system power threshold. Numerical results show that the presence of small cells improves the total sum rate compared to relying on the macro base station alone under the same total system power constraint.