准平坦地形GSM-R电波传播特性研究

城市的电波传播以衍射机制为主,其大尺度衰落特性的预测通常采用基于统计模型的Okumura模型和Hata模型。这两种模型未考虑小尺度衰落。同时,如果对准平坦环境下高速铁路GSM-R信号的大尺度衰落预测,还需要进行适当的修正。本文首先对准平坦地形下铁路沿线GSM-R电波传播进行理论分析,认为其传播方式以一条直射路径和若干条反射路径为主。然后建立起4路径仿真模型。通过该模型计算得出小区各个位置场强分布,同时得到大、小尺度衰落特性。最后对仿真结果和实测结果进行统计分析,统计结果显示了模型的有效性。

Research of the Electromagnetic Wave Propagation in GSM-R System with Quasi-flat Terrain

Diffraction is the main way by which electromagnetic waves propagate in urban areas.Its large-scale fading may be estimated by the Okumura and Hata models.However,small-scale fading has not been taken into consideration in the above two models.The above two models need to be modified to estimate the large-scale fading of the GSM-R system in the quasi-flat terrain.It can be understood that the electromagnetic waves in the quasi-flat terrain usually propagate to the receiver by the line of sight(LOS) or by a few reflection ways.Based on the above analysis,the 4-way simulation model was established.Both the large-scale and small-scale fading properties can be obtained from the model.The statistics of the simulation results are close to the measured results,showing the validity of the simulation model.