蒙特卡洛方法用于城镇5G基站电磁暴露安全评估

The electromagnetic field exposure assessment based on Monte Carlo method for 5G base station in urban area

电磁暴露安全是当前5G通信在大规模商业化推广过程中需高度重视的问题.大规模多输入多输出(multiple-input multiple-output,MIMO)和天线3D波束成形等技术在现有5G基站中已得到成熟应用,但以往传统确定性方法在评估该类基站时过于保守,很难得到准确可信的基站电磁暴露评估结果.本文在以往基于蒙特卡洛(Monte Carlo,MC)统计方法的5G基站电磁暴露评估模型基础上,进一步模拟构建了城镇基站小区的三维用户场景,采用电磁暴露相对因子作为衡量指标实现了更真实用户场景下的5G基站电磁暴露水平评估.结果表明,在文中给定的两类基站配置参数下,5G基站小区在最坏情况下电磁暴露相对因子计算结果最大值仅有保守确定性方法给出的电磁暴露评估结果的25%左右,说明5G基站引入大规模MIMO和波束成形技术后不仅改善了用户通信质量,同时也使覆盖区域内电磁暴露量值分布更为均匀,得到了比传统基站更低的电磁暴露水平.

The safety of electromagnetic exposure induced by 5G base station has become a big issue accompanied with its large-scale commercial application.To solve the assessment of 5G base station equipped with massive multiple-input multiple-output(MIMO)and 3D beam forming technology,this paper proposes an improved statistical approach based on the previous Monte Carlo method to evaluate the electromagnetic field(EMF)exposure.As a studied case,a three-dimensional user scenario located in urban area is built to demonstrate the implementation process of this novel method.The result shows that the proposed relative EMF exposure factor is less than 25%when assuming the worst-case scenario,same equivalent radiated power and mounting height for both the 5G and 4G base station.Moreover,when comparing with the 4G base station,a reduced and uniform field distribution is obtained due to the random beam direction and time average in 5G base station.