中文摘要：

信道模型是卫星移动通信系统设计和线路设计的基础．主要研究了陆地卫星移动通信独立阴影衰落信道模型，2个相互独立的对数正态随机过程分别作用于直射信号分量和多径散射信号分量，接收信号包络是一个对数正态分布分量与另外一个对数正态分量与瑞利分量乘积之和．给出了该模型的电平通过率和衰落持续时间．累积分布仿真结果与理论分析计算结果的比较证明了模型的有效性．

英文摘要：

A channel model to the land mobile satellite communications is described, in which two indepen- dent Log-normal random processes effeeted on the LOS signal and the muhipath signals, respectively. The received signal is the sum of two components, the Lognormal component and the other component, which is the product of the Rayleigh and the second Lognormal. The second order statistic characteristics, level cross ratio and average fading duration, of the model are derived. The consistence of the simulation and the analytical results is showed by the figures.