Energy Efficiency Optimization Scheme For Multi Cell MU-Massive MIMO

Massive MIMO attracts much attention because it is a potential key technology in mobile communications in the future.As the extension of the traditional MIMO,Massive MIMO takes the advantage of the numerous antenna compared to the traditional MIMO.It excavates resources on spatial dimension furtherly by configuring a large scale of antenna array on the side of the base station,and serves more users on the same time-frequency resource block,improving the energy efficiency and frequency efficiency of the system significantly.However,in the Massive MIMO system,it needs to configure the same RF link as the transmitting antenna on the side of the base station.When all antennas are opening for data transmission,the power consumption of the circuit is very huge and the transmission is highly complex,and it cannot achieve optimal efficiency of system when considered the perspective on energy efficiency.Nevertheless,activing some antennas on the side of base station and adjusting the transmission power can reduce power consumption and lower the transmission complexity while realizing higher energy efficiency.Based on this theory,this paper makes further research and analysis on the optimization of energy efficiency of Massive MIMO.Firstly,this paper introduces the related knowledge of Massive MIMO,including basic application of Massive MIMO and precoding technology.Then the paper analyzes the single-user system model and multi-users system model to verify the advantages of Massive MIMO system and the feasibility of linear pre-encoding,introducing some of existing schemes of energy efficiency optimization of the two system models in detail.Secondly,the paper analyzes and validates a scheme of energy efficiency optimization for downlink of multi-users Massive MIMO system in a single cell.The scheme bases on antenna selection algorithm to find the optimal number of antennas that maximize energy efficiency,explaining that the stochastic antennas selection algorithm performs is close to optimal performance when the number of antennas is huge.The simulation result shows that the proposed scheme can significantly improve the energy efficiency of the system,compared with the opening of antennas on the side of base station.However,the contrast of parameter variation suggests that the proposed scheme only considers optimization on the number of transmit antennas but does not consider problems such as transmitting power regulation and so on.Finally,in order to solve the problems in the scheme,the author puts forward a new scheme of energy efficiency optimization for downlink of multi-users Massive MIMO system in multi cells.Different from the original scheme,this new scheme combines fractional programming method with the parameters,calculates the relationship among emission power,antenna number and energy efficiency as a derivation,giving an energy optimization scheme of the iteration between emission power and the number of active antennas.The simulation result shows that this new scheme improves a lot in terms of energy efficiency and has a certain advantage over the original scheme.