基于马尔科夫链的两状态卫星移动信道模型

Markov chain based two-state satellite mobile channel model

针对卫星移动信道概率统计的单状态模型只能描述单一信道环境，而多状态模型随着状态数目的增多参数也越多、仿真也越复杂的问题，本着模型既要准确反映实际信道传播特性，同时又要相对简单、容易实现的原则，采用滤波器法和马尔科夫链实现了一个包含“理想状态”和“非理想状态”的广域环境两状态信道模型的动态仿真。通过在我国本土环境下得到的铱星系统信道特性实测数据，利用最小均方误差准则和线性最小二乘法拟合出了该模型在我国三种典型真实信道环境（开阔地轻阴影遮蔽环境、乡村中等阴影遮蔽环境以及城区重阴影遮蔽环境）下的参数，该模型的有效性得到了验证。

Considering that a single-state probability statistical model for satellite mobile channels can only describe a single channel environment, while a multiple-state model brings more parameters and more complicated simulation work, the dynamic simulation of a two-state （ both the ＂ideal state＂ and the＂ non-ideal state＂ ） channel model under a wide-area environment was implemented with the filter method and the Markov chain method, according to the principle that the model should accurately depict the real transmission characteristics of the channel with the relative simplicity and feasibility. Based on the experimental data of the iridium system measured by the Communication Research Center, Harbin Institute of Technology, the modeling parameters under three kinds of typical channel environments were fitted by using the least squares error criterion and the method of linear least squares, and the effectiveness of the model was verified.