Energy efficiency analysis of millimeter wave mimo systems with hybrid subarray architecture

Abstract

Millimeter-wave (mmWave) systems are promising to enable much higher data rates, thanks to transmission bandwidth on the order of GHz, in 5G cellular system than those in commercial wireless systems. This paper considers a mmWave system where the base station employs a hybrid analog-digital beamforming based on a subarray architecture. Based on a realistic circuit power consumption model that takes into account different signal processing steps at the transmitter, we analyze the energy efficiency (EE) of the system, which is defined as the ratio of the sum achievable rate over the total power consumption. We also provide the globally EE-optimal value of the transmit power when the channel inversion based baseband precoder is employed.