Research On Energy Efficiency Technology Of Distributed MIMO System

The next-generation mobile network greatly exceeds the transmission rate of 4G,and quality of service has been greatly improved compared to the previous-generation mobile network.However,with the evolution of communication system,the energy lost is also getting worse.How to improve the effective utilization of resources while ensuring system performance,is becoming the most important problem in green communication of the next generation.The Distributed MIMO(Multiple-Input Multiple-Output)system is one of the core technologies of the new generation of mobile networks.It combines the advantages of traditional MIMO technology and Distributed Antenna Systems(DAS),and can significantly increase system capacity and increase the coverage of the signal.Therefore,research on the green communication technology of distributed MIMO systems has practical application significance.The paper studies the energy efficiency of distributed MIMO systems based on the National Natural Science Foundation of China's "Investigation of Energy Efficiency Technologies for Distributed Antenna Mobile Communication Systems"(61601300).The main work of this paper is as follows:1)The energy efficiency of distributed MIMO system based on interrupt capacity is studied.Firstly,a single-user distributed MIMO system is modeled and the mutual information expressions of ergodic capacity and interrupt capacity are given in two cases,respectively.Based on the actual power loss model and the ideal power loss model derive an energy efficiency expression,respectively.According to the energy efficiency expression,the nature of the energy efficiency based on the interrupt capacity is theoretically studied.The simulation results prove that there is a trade-off relationship between the energy efficiency based on the interrupt capacity and the actual power loss.Then based on the energy efficiency model of the distributed MIMO system based on the interrupted capacity,the relationship between the cell radius,outage probability and path loss index and the energy efficiency and interrupting capacity is simulated and analyzed.2)In order to maximize the energy efficiency of distributed MIMO systems,the first part studies the problem of power allocation optimization to maximize energy efficiency and presents the algorithm flow chart of the power allocation algorithm based on the sub-gradient method and the traditional power allocation.The simulation results show that the sub-gradient power distribution method with energy efficiency as the optimization goal can reduce the energy consumption while ensuring the system capacity.This shows that designing a power distribution scheme based on energy efficiency can achieve a compromise between system capacity and energy consumption.Further,in order to improve the energy efficiency of the distributed MIMO system,an optimization algorithm based on path loss information is proposed.In order to achieve the purpose of improving system energy efficiency,The algorithm uses the path loss information as a criterion for antenna selection and then performs power allocation after matching with the target antenna.The simulation results show that within a certain range,as the number of antenna selections increases,the performance of system capacity and energy efficiency increase.