  In this paper, we investigate the energy efficient power allocation for the
downlink in the massive multiple-input multiple-output (MIMO) systems under
zero-forcing (ZF) receiver. The radio frequencies (RF) that have a significant
effect on system performance has not been considered in most of previous
researches. Increasing of random changes in RF creates a mismatch channel. We
must consider the effects of the RF circuit for the performance evaluation of
the massive MIMO systems. We also consider the rate of system in the presence
of estimation error, similar to real world, with the quality of service (QoS)
constraint and the transfer capacity of users. In the scenario of this paper,
users are divided into two groups. The first group are users who have stronger
channel conditions or in other words are located in the center of the cell, and
the second group belongs to users who have weak channel conditions and are
located at the edge of the cell. By using Karush-Kuhn-Tucker (KKT) conditions,
we obtain the optimal power of users. The results of implementation and
simulations are given to confirm the efficiency of the proposed algorithm.
