QoS-Guaranteed Energy And Throughput Joint Optimization In Multi-User MIMO Systems

The past decades has witnessed the rapid development in wireless communications,a very broad and dynamic field.MIMO systems can increase channel throughput without occupying additional spectral bandwidth.There are two types of MIMO systems: SU-MIMO and MU-MIMO.In SU-MIMO,different users occupy different time-frequency resources.But MU-MIMO allows multiple users share the same time-frequency resources via space division multiplexing,which further increases the spectral efficiency.Thus MU-MIMO has been widely used in wireless communications nowadays.As the number of antennas rises,the consumption of electric energy also increases.Green communications has drawn a lot of attentions in current researches.Thus,the concept of energy efficiency(EE,represented by transmission data rate per unit energy)has emerged as the optimization goal in wireless telecommunication systems.It is imperative to pursue the balance among energy efficiency,throughput and QoS requirements.In current researches,however,focus only on energy efficiency or throughput.This paper proposes a finely QoS-guaranteed algorithm to jointly optimize the throughput and energy efficiency in MU-MIMO systems.The latency requirements of real-time services are guaranteed by user scheduling in the first stage.The energy efficiency and system throughput are jointly optimized while the required transmission rate is finely guaranteed in the second stage.Simulation results show that the algorithm can achieve a good balance between the energy efficiency and throughput,and is superior to the existing schemes in terms of QoS guarantee.