高速铁路环境下多输入多输出信道容量分析

摘要

根据高速铁路环境,在接收机已知信道状态信息(GSI)而发射机未知CSI的条件下,研究窄带和宽带多输入多输出(MIMO)信道容量计算方法.采用该方法对算例仿真的结果表明:莱斯因子对MIMO信道截止容量的影响较大,对遍历容量的影响则可以忽略不计；MIMO信道容量随着天线数量的增加而显著增加,但并非线性增加；当采用均匀线阵(ULA)时,基站和移动台天线垂直于铁路线路方向放置可以获得更大的信道容量；ULA的天线间距以10倍波长为宜；合理配置天线,在高速铁路环境下,MIMO信道也可获得较高的容量.%The paper investigates MIMO channel capacity in high-speed railway environment under the assumption that the channel state information (CSI) is unknown at the transmitter and perfectly known at the receiver, and studies the computation approaches for the ergodic capacity and outage capacity of both narrowband and wideband MIMO channels. We carry on the simulation to the computation approaches. Simulation results show that; Rice factor (K factor) has significant impact on the outage capacity of MIMO channel, while has little impact on ergodic capacity. MIMO channel capacity increases with the number of antenna arrays, but does not increase linearly. The orientation of Uniform Linear Array (ULA) in base station and mobile station should be vertical to railway line to gain more capacity. The appropriate spacing of ULA is about ten times of the wavelength. MIMO channel can achieve higher capacity in highspeed railway environment with appropriate configuration of antenna arrays.