Abstract: In order to promote the application of 5G communication system Massive MIMO technology in subway, this paper uses ray tracking to predict the impact of different array layouts on the performance of Massive MIMO systems in tunnel scenarios. The ray tracking method is calibrated, the relevant parameters in the tunnel scenarios are determined, and the system capacity, path loss and mean square root delay under the layout of various antenna arrays in MIMO system are analyzed through the ray tracking simulation of 160 M bandwidth centered on 5.6 GHz, which is of reference to the antenna and base station design in 5G communication system.

Key words: Massive MIMO, antenna arrays, ray-tracing, channel characteristics, subway tunnel

摘要： 为推广第五代无线通信系统（5G）大规模多输入多输出系统（Massive MIMO）技术在地铁中的应用，使用射线跟踪预测在隧道场景中，不同阵列的布局对Massive MIMO系统性能的影响。对射线跟踪法进行校准，确定隧道场景下的相关参数，通过以5.6 GHz为中心的160 M带宽的射线跟踪仿真，分析Massive MIMO系统中多种天线阵列布局下的系统容量、路径损耗以及均方根时延，对5G通信系统中的天线与基站设计有参考意义。

关键词: MIMO, 天线阵列, 射线追踪, 通道特征, 地铁隧道