基于三维空间模型的毫米波蜂窝网络覆盖概率分析

毫米波蜂窝网络通常在二维空间下建模和性能分析.二维模型适合基站分布稀疏的郊区,但是并不适合城市环境下密集蜂窝网络的性能分析.基于随机几何理论提出三维空间模型.该模型假设基站分布为三维泊松点过程;阻碍模型为视距(line of sight,LOS)球模型;信道为Nakagami-m衰落信道;收发端使用大规模天线阵列获得最大的波束成形增益.基于该模型,给出了三维空间下目标用户和最近基站距离的概率密度函数,推导出目标用户的平均覆盖概率,通过蒙特卡洛仿真实验与二维模型的性能进行了对比,分析了路径损耗、蜂窝半径、天线的波束宽度和天线增益等参数变化对平均覆盖概率的影响.实验结果表明,在密集的城市环境下,三维模型对毫米波蜂窝网络的性能分析更加精确.

Coverage probability analysis of millimeter wave cellular networks based on three dimensional space model

Millimeter wave cellular networks are usually modeled and analyzed in two dimensional space. The two dimensional model is more suitable for the performance analysis of sparse cellular networks in suburban environments than that of dense cellular networks in the urban. Therefore, we propose a three dimensional space model based on stochastic geometry in the paper. The model assumes that the base stations are modeled as a three dimensional Poisson point process, the blockage is modeled as LOS ball, the channel is modeled as Nakagami m fading, and the transmitters and receivers use a large array of antennas to obtain maximum beamforming gain. Based on the model, the probability density function of the distance between the typical user and the nearest base station is given, and then the average coverage probability of the typical user is derived. Through Monte Carlo simulation, we compare the performance of the proposed model with two dimensional model and analyze the impact of parameters such as path loss, cell radius, antenna beam width and gain of antenna on average coverage probability. The simulation results show that in the dense city environment, the performance of three dimensional model of the millimeter wave cellular network analysis is more precise.