中文摘要：

对隧道中电磁波传播特性进行研究是发展隧道环境下无线通信系统的基础。近年来,研究人员多关注于隧道环境下的电波传播特性,而较少考虑到车体对通信系统性能的影响。在车体的影响下,信号在穿越车体时会发生功率损耗,同时反射物的增加会使反射线增多,其对信号功率在车体内的分布、天线相关性、角度特征以及MIMO性能的影响还需要进一步研究。使用射线跟踪法,在隧道环境下引入车体模型,分析对比了有车和无车时的车体内功率分布与路径损耗,并从角度特征、天线相关性、特征值、容量等方面分析各类因素对MIMO性能的影响,为隧道环境下应用多天线技术提供参考依据。

英文摘要：

The investigation of electromagnetic wave propagation characteristics in tunnels is the foundation of developing wireless communication system under the tunnel environment.In recent years,many researchers have mainly studied the propagation characteristics of wireless electromagnetic wave in tunnels,but few literatures focused on the impact of carriage on the performance of the communication system.Affected by the carriage,the signal experiences power loss when passing through the carriage,and more echo rays will be received with the increase of the reflectors.Further efforts are required to investigate the influences of the carriage on the signal power distribution in the carriage,antenna correlation,angle characteristic and MIMO performance.In this paper,ray tracing method was used in a tunnel model to simulate the power distribution and path loss in tunnel with and without the carriage.In addition,the influence of various factors on the performance of MIMO was analyzed from the aspect of angle characteristics,antenna correlation,singular value and capacity,which provides reference basis for MIMO application in tunnel scenarios.