This paper proposes a new energy efficiency (EE) model with circuit power consumption in downlink massive multiple-input multiple-output (MIMO) systems, and analyzes how the number of transmit antennas and the transmit power affect the EE. A concise model of the distribution of the mutual information and a new realistic power consumption model are used to draw a closed-form expression for the EE model. Mathematical analysis proves that the EE is a concave function of the number of transmit antennas and the transmit power, and the EE increases first and then decreases as the transmit power increases, indicating the existence of the optimal number of transmit antennas and the transmit power. An iterative algorithm is given to compute jointly the optimal number of transmit antennas and the transmit power. Simulation results show that when the circuit power consumption is comparable to the transmit power, there exists an optimal number of transmit antennas to maximize the EE.
['Shunyuan Dong', 'Ying Wang', 'Lisi Jiang', 'Yongce Chen']
Energy Efficiency Analysis with Circuit Power Consumption in Downlink Large-Scale Multiple Antenna Systems