摘要
在目前的城市轨道交通车地通信系统中,通常存在漏泄波导与无线自由波两种传输方式。本文介绍这两种不同的车地通信方式,分析漏泄波导的信道模型,并指出其信道模型近似于高斯信道。根据城市轨道交通车地通信的高架环境,研究车地无线自由波通信存在强烈直射径的情况下,2×2天线MIMO系统的信道容量及天线间距,得出最佳的天线间距及配置方案。将此MIMO系统的信道容量与漏泄波导的信道容量进行比较,结果表明MIMO系统的信道容量优于漏泄波导信道。
In current train-wayside communication systems applied in urban rail transit ,there exist two propaga-tion mediums ,i .e .,the leaky waveguides and wireless free waves .In this paper ,the two different communica-tion modes were described .The channel model of leaky waveguids was analyzed and shown to be approximate to the Gaussian channel .The channel capacity of 2 ×2 MIMO antennas with LOS components in the elevated rail environment was studied and the optimal antenna spacing distances were calculated according to theoretical derivation .At last the channel capacities of the two propagation mediums were compared .The results show that the channel capacity of 2 × 2 MIMO is better than that of leaky waveguides .
出处
《铁道学报》
EI
CAS
CSCD
北大核心
2014年第8期44-48,共5页
Journal of the China Railway Society
基金
国家自然科学基金(61132003)
北京市科技计划课题(D13110000 4113002)