基于雨衰雪衰影响的空间信道统计模型

针对某些特殊的移动通信环境中信号的到达角度（TOA）、到达时间（AOA）等信道参数估计的复杂性，提出一种基于散射体均匀分布室外统计信道模型。该模型将树木中的树冠层作为散射体呈均匀分布在移动台与基站周围的椭圆形区域内，通过树冠层在雨雪环境中的相对介电常数来分析降雨降雪量对信号传输带来的影响，可以方便地估计出此室外微小区的空时信道参数，如AOA概率密度分布函数、TOA概率密度分布函数以及到达角度/到达时间（AOA/TOA）联合概率密度分布函数。仿真结果表明，信号的到达时间TOA以及到达角度AOA随着降雨降雪量的增大而增大，尤其当降雪量增大使得树冠层相对介电常数达到4.5时，信号的传输将被阻塞。该模型的信道参数估计结果符合理论与经验，扩展了移动无线通信信道模型的研究与应用。

A geometrical statistical channel model based on rain and snow fading effect

For the complexity of channel parameters estimation for angle of arrival(AOA) and time of arrival(TOA) in some special mobile communication environment,an outdoor statistical channel model based on the uniform distribution of the scatterers is proposed.In this model,the canopy of tree is distributed evenly in the oval area around the mobile station and the base station.The influence of rainfall and snowfall on the signal transmission is analyzed by the relative permittivity of canopy layer in wet environment.Closed-form expressions for marginal and joint probability density function(PDF) of AOA,TOA in the outdoor macrocell wireless environment are derived.The TOA and the AOA of the signal increases with the increasing of the amount of rainfall and snowfall.In additional,the signal will be blocked when the the relative permittivity is equal to 4.5.Channel parameter estimation results of the model show that the analysis is correct and applicable to macrocell environment,which promotes the research on mobile communication channel model.