高速铁路路堑场景的车车通信无线信道建模研究

Mobile to mobile wireless channel modeling in high-speed railway cutting scenarios

针对传统几何随机分布模型(GBSM)对高速铁路路堑场景适用性不强,列车无线通信系统建模方法不能体现出无线信道的非平稳特性等问题,基于GBSM建模方法及高斯马尔科夫移动模型(GM模型),建立高速铁路路堑场景下的车车通信无线信道模型,模型中假设实际散射体为随机分布在发射端和接收端的虚拟圆柱体表面的等效散射体,且接收端和发射端的运动速度及运动方向均随机,分析信道统计特性中的时变特性,并通过时变时间特性展现信道的非平稳特性。研究结果表明,信道的非平稳特性随着GM模型中随机参数的变化而变化,发射端与接收端速度变大、信道各向异性增强,信道的非平稳特性增强,证明无线信道只有在速度和方向均时变的条件下,才具有非平稳特性。

The traditional Geometry-based Stochastic Model(GBSM)is not suitable for high-speed railway cutting scenarios,and the modeling method of train wireless communication system can not reflect the non-stationary characteristics of wireless channel.Based on modeling method of GBSM and the Gauss-Markov Mobility Model,it established SISO M2M two-cylinders Gauss-Markov mobility model in order to further guarantee the safe operation of high-speed railway and study the non-stationary of the wireless channel model of railway.In the model,it assumed that the actual scatterers were equivalent scatterers on virtual cylinder randomly distributed at the transmitter and the receiver,and the movement velocity and direction of both were random.In addition,it analyzed time variant characteristics in channel statistical characteristics,and the non-stationary of the channel was shown through the time variant characteristics.According to simulation results,the non-stationary of the channel varies with the random parameters in Gauss-Markov mobility model.The velocity of the transmitter and the receiver get faster,and the channel non-isotropy is enhanced,so is the non-stationary of the channel.It is proved that the wireless channel has non-stationary characteristics only when the speed and direction are time-varying.