陆地高速移动环境下电波传播特性的建模与分析

Simulation and analysis of radio wave characteristics in terrestrial high-speed mobile environment

采用有限状态的马尔克夫链得出陆地高速移动环境下电波传播路径的动态仿真模型。将模型与真实的陆地高速移动电波传播环境相结合,建立了更符合实际传播环境的电波传播仿真模型,通过该传播模型得出陆地高速移动环境下的电波传播特性。将得出的模型运用于较平坦地理环境,基站信号覆盖区域约为3km,存在视距(LOS)路径。通过仿真给出了高速列车在沿线不同位置和不同速度时的电波路径数目、各电波路径的衰减系数、延迟时间等,以及由此分析计算出的在该环境下的多普勒频谱、电平通过率等电波特性。最后,对这些仿真数据进行统计分析,证实了该传播模型的有效性。

The finite states birth and death Markov chain is used to model the wireless propagation paths in land high-speed mobile environment. A more realistic terrestrial high-speed mobile radio propagation model is set up with the parameters of the real operation surroundings and conditions. Based on this model, the characteris- tics of radio propagation can be analyzed. In this paper,one simulation under the rural high-speed ＇train scenario ,where wireless coverage is provided by base station at every 3 kilometers interval and the link between the fixed base station and the moving train was typically a line-of-sight（LOS） type, is operated with the above model. Through the simulations at different velocities（300 km/h and 500 kin/h）, the changing link paths and their attenuation coefficients, delay times, Doppler spectrums and cross rate can be obtained. Moreover, this model is proved to be effective according to plenty of simulated data statistics.