Research On Energy Efficiency And Antenna Selection Algorithm In Large-scale Multiple Antenna Systems

With the development of mobile Internet business and the explosive growing of data business,the requirements of the mobile communication quality are becoming higher and higher.As the long-term evolution(LTE)system embodying 4G has now been deployed and is reaching maturity,more and more researchers pay their attention to the field of the new technology of 5G.As one of the important technologies of 5G,massive multiple-input multiple-output(MIMO)plays an important role in improving the performance of 5G systems.The problem of energy efficiency(EE)has always been a set-back of the sustainable development of human society.Energy conservation and emissions reduction become more and more emergent in all walks of life,including the field of wireless communication.In 5G systems,EE has become an important subject and is one of the critical performance indicators.Therefore,it becomes one of the focuses in this thesis.Although large-scale antenna technology can improve the capacity of the system,at the same time it will greatly increase the complexity of the system and cause the decrease of the EE.Excellent antenna selection can greatly reduce the system complexity and improve the system EE on the premise of not sacrificing system capacity.Therefore,this thesis also proposes an antenna selection algorithm.First,the EE of large-scale antenna system and the theory of antenna selection is discussed.The concept of EE in the communication system as well as the importance of the EE study in large-scale antenna system is introduced.Furthermore,the antenna selection techniques in traditional MIMO and large-scale antenna system are discussed and compared.Second,according to the concept of average mutual information and the actual circuit consumption model,the EE of the large-scale antennasystem is modeled.An EE optimization problem is formed based on the transmitting antenna number and transmitted power.This optimization model is studied fully by mathematical derivation and simulation verification.The relationship among the transmission power,transmit antenna numbers and the EE is discussed,and an jointly optimal algorithm is given.Then,the antenna number selection algorithm is discussed,while the performance of the transmit antennas is unknown.When the performance of the antennas is known,this thesis proposes a joint antenna selection algorithm.The complexity of antenna selection algorithms under the two different scenarios are studied by the principle of optimal EE.Moreover,the feasibility and superiority of the joint selection algorithm is proved by mathematical derivation and simulation verification.Finally,the thesis summarizes the research on the whole,and the difficulties of the future study are prospected.