隧道中UHF窄带无线电波传播信道的特性

Characterization of Narrow Band UHF Radio Propagation Channels in Tunnel Environments

本文以在五个不同隧道中的实验数据为基础，分析了窄带ＵＨＦ无线电波在隧道中的传播特性，给出了表征空直隧道传播损耗的距离因子，并讨论了隧道中的行人、车辆及隧道弯曲度对传播特性的影响。研究表明，接收信号的慢衰落基本服从对数正态分布，快衰落在直遂道中满足Ｒｉｃｉａｎ分布，在弯曲隧道中Ｒａｙｌｅｉｇｈ分布并不能很好地模拟快衰落的分布。

Propagation measurements taken in five tunnels at 900 and 1800 MHz for microcellular and personal communication are presented.The power distance factors to characterize propagation loss in straight empty tunnel section are given.The effects of pedestrians,vehicle,and curvature on propagation are also investigated.Furthermore,it is found that The log normal distribution basically fits the slow variation of the received signals.Whereas the Racian distribution closely models the fast fading in the straight empty sections of the tunnels,however,the Rayleigh distribution does not fit the fast fading in the curved section of the tunnels as well as expected.