Green communication network: Large antenna arrays with linear precoders

Zero-forcing (ZF) precoder is generally the simple precoder in Mu-MIMO system, but this precoder design has a large complexity by the inverse matrix in a large antenna arrays. In this paper, therefore, we study the linear precoders for the multi-user large antenna arrays and power allocation method to enhance the energy efficiency of the system while meeting quality-of-service (QoS) of each users. When the number of antennas at the transmitter is large, we find that ZF and MMSE precoders are approximately the same in the senses of power allocation and received SINR. Simulation results confirm that the performance of approximated precoders are similar to that of ZF precoder in case of many transmit antennas.