On the impact of power amplifier efficiency on the energy efficiency in a massive MIMO system

It is a practical challenge for wireless communication system designs to achieve both high spectral efficiency and energy efficiency because of the nonlinear effect and inefficiency of power amplifier. In previous work, the power amplifier efficiency is always considered as a constant, but it changes with the output power in reality. In this paper, we talk about the impact of variable power amplifier efficiency, propose an energy efficiency model considering power amplifier efficiency as a variable, and investigate a power allocation scheme based on zero-forcing precoding so that we can guarantee the spectral efficiency and energy efficiency at the same time. Simulation result shows the trade-off between energy efficiency and spectral efficiency, and implies that relatively higher transmit power will be more energy efficient.