雨衰环境下的自适应调制的应用

摘要

卫星通信优化调制系统要保证信号传输质量,降雨率和雨区分布情况严重影响了信息的传输质量和限制了系统的可靠性.雨衰是影响卫星通信链路中断的主要因素,频率越高越明显.为了克服这种情况,采用自适应调制的方法,研究基于突发情况的快速自适应调制技术,以瞬时的信噪比作为判别门限,采用不同的调制方式,从而达到提高整个通信系统的吞吐率的目的.以铱星系统为背静,OPNET软件为工具,真实地仿真了自适应调制在雨衰情况下的应用.结果证明,提高了自适应调制效果.%Rain attenuation is a dominant source of satellite link outages in higher frequencies satellite communication systems.The intensity and distribution of rainfall greatly affect transmission quality and limits system's availability.In order to overcome such difficulties, in the article, adaptive modulation is used and SNR istaken as the judgement threshold.This method improves the throughput in satellite communication.With Iridium System as the back and OPNET as tool, the application of adaptive modulation is simulated veritably under the environment of rainfall.Comprehensive theoretical analysis and dedicated simulations show that the simulation results and the theoretical results are matched perfectly.