In this letter, we investigate the energy efficiency (EE) problem in a millimeter wave massive MIMO system with non-orthogonal multiple access (NOMA). Multiple two-user clusters are formulated according to their channel correlation and gain difference. Following this, we propose a hybrid analog/digital precoding scheme for the low radio frequency chains structure at the base station. On this basis, we formulate a power allocation problem aiming to maximize the EE under users' quality of service requirements and per-cluster power constraint. An iterative algorithm is proposed to obtain the optimal power allocation. Simulation results show that the proposed NOMA scheme achieves superior EE performance than conventional OMA scheme. Index Terms-Massive MIMO, millimeter wave, hybrid precoding, energy efficiency, NOMA. Fig. 1 . Cluster-based downlink mmWave mMIMO-NOMA system model.
In REF , the authors propose a hybrid analog/digital precoding and power allocation scheme to maximize the EE of the system.
Energy-Efficient Power Allocation in Millimeter Wave Massive MIMO With Non-Orthogonal Multiple Access
IEEE Wireless Communications Letters
IEEE Wireless Communications Letters
Mathematics Computer Science