动中通车载站可用性分析

与固定卫星通信系统相比,移动卫星通信系统中的地球站在通信过程中是运动的,因此其通信的电磁环境是极其复杂的,存在多径衰落、多普勒频移、阴影效应,在进行系统设计时,必须对它们造成的影响进行充分考虑。首先对移动卫星信道特性进行了分析,接下来给出了系统设计中几项主要指标的考虑方法,最后给出了采用最佳译码方案、分层传输技术和自适应误码掩盖等提高系统可用性的几项措施的讨论。

Availability Analysis on Vehicular Station of Mobile Satellite Communications System

Compared with fixed satellite communications system,the earth station in mobile satellite communications system is moveable during the communication.In this complicated electromagnetic environment where some impacts exist,such as multi-path fading,Doppler shift and shadowing effect,full consideration is necessary in the calculation of system design.Firstly,the author analyzes the features of mobile satellite channel,then gives some consideration methods for those main specifications in system design,and finally discusses some measures,such as the best decoding scheme,hierarchical transmission technology and adaptive error concealment,which may improve the system availability.