火星信道衰落特性对通信链路预算的影响

对火星星体段的信道衰落特性进行研究.通过对近火段自然环境因素的分析，提取影响火星通信性能的因素，重点分析火星的大气、云雾、沙尘对通信信道的衰落作用机理；并以NASA实际火星探测任务为例，针对以上衰落因素对UHF，S，X和Ka频段下的通信链路影响情况进行仿真；结合实际探测数据对地球通信链路预算模型进行修正，提出一种适用于火星通信链路预算的模型；明确火星大气衰落、云雾衰落、沙尘衰落的取值范围.研究结果可作为火星及其他深空探测任务的通信系统设计与链路复核复算的参考. 

Influence of Mars Channel Fading Characteristics on Communication Link Budget

The communication distance between Earth and Mars is far away, and there are many factors affecting the Mars communication link. In order to facilitate analysis and calculation, the Mars communication link is generally divided into three parts, the near Earth segment, interplanetary space segment, and near Mars segment. Focus on channel fading characteristics in the near Mars segment, the factors affecting Mars communication performance are extracted from Mars natural environment. Focus on theoretical analysis of the fading effect of Mars atmosphere, cloud and dust on the communication channel, and the actual Mars exploration mission of NASA is taken as an example to simulate the influence of above fading factors on communication link in the UHF, S, X and Ka band. Based on actual detection data, a model that suitable for Mars communication link budget is proposed on the premise of correcting the model of the Earth communication link budget. It can determine the range of Mars atmospheric fading, cloud fading and dust fading. The results can provide a reference for communication system design, link review and recalculation for Mars and other deep space exploration missions.