Modeling And Performance Analysis Of Millimeter Wave Heterogeneous Cellular Networks

In recent years,due to the booming development of the mobile Internet industry,the demand for mobile communication data has exploded,so the research and development of the fifth generation(5 gengeration,5G)mobile communication technology is in progress.The rapid growth of mobile users and wireless traffic has caused a new generation of communication systems to face a serious shortage of spectrum resources.There are a large number of available spectrum resources in the millimeter wave band,which can effectively solve this problem.Therefore,millimeter wave communication is one of the key technologies of 5G communication.Millimeter-wave heterogeneous cellular networks enable networks to achieve higher data rates and greater coverage.Based on the theory of stochastic geometry,this paper models and analyzes the millimeter-wave heterogeneous cellular network.The main research work has the following three aspects:1.A two-layer network model is constructed for a non-uniform millimeter-wave heterogeneous cellular network that is closer to the actual scene.In this model,the macro base station distribution is modeled by the homogeneous Poisson point process,and the pico base station distribution is modeled using the Poisson hole process.Based on the model,the theoretical expressions of coverage probability and rate coverage probability are derived by using the stochastic geometric theory tool.The accuracy of the theoretical expression is verified by Monte Carlo simulation,and the influence of system parameters on the coverage probability is analyzed.The experimental results show that the optimal density value exists in the picocell base station,so that the performance of the coverage probability is optimal.At the same time,under this model,the rate coverage probability of millimeter waves is better than that of microwaves.2.For the dense distribution of millimeter-wave heterogeneous base stations in urban environments,three-dimensional(3D)spatial models are used to analyze the performance of millimeter-wave heterogeneous cellular networks.First,it is assumed that the distribution of base stations in each layer obeys the three-dimensional Poisson point process,and the path loss intensity function of the ball barrier model in the three-dimensional space is derived.Then,the maximum bias received power access criterion is adopted.It is assumed that the transceiver uses a large-scale antenna array to obtain the maximum beamforming gain.Under the Nakagami fading channel,the coverage probability expression of the target user is derived.Finally,the performance of Monte Carlo simulation and two-dimensional space model are compared,and the influence of system parameters such as ball barrier model,base station bias factor and antenna gain on coverage probability is analyzed.The experimental results show that the performance analysis of the millimeter-wave heterogeneous cellular network is more accurate in the three-dimensional model.3.Analyze the energy efficiency of 3D millimeter wave heterogeneous cellular networks.In the actual deployment of millimeter-wave heterogeneous cellular networks,energy efficiency will become an important performance indicator.Based on the three-dimensional model of millimeter-wave heterogeneous network,this paper analyzes the energy efficiency index of the system and derives the theoretical expression of the energy efficiency of millimeter-wave heterogeneous cellular network.The accuracy of the formula was verified by Monte Carlo simulation experiments,and the influence of system parameter changes on energy efficiency was analyzed.Experimental results show that reasonable setting of base station offset and base station density can maximize energy efficiency.