The Study Of The Character Of Rain Attenuation And Compensation Methods Of The Ka-band Satellite Communication System In Yanatze River Delta

With the rapid development of millimeter wave,satellite communication has become an important part of the integration of global communications,medical care and education.Using Ka-band satellite communications is not only an inevitable trend to the military applications,but also a technological innovation to the new high-speed satellite communications business which provides a new meaning in civilian areas.However,with the rising of frequency in Ka-band communication,rain attenuation is relatively serious.In order to impove the quality of the satellite link transmission,some methods must be taken to compensate the rain attenuation.Firstly,for the complexity of channel parameters estimation for AoA(Angle of Arrival)and ToA(Time of Arrival)in some special mobile communication environments,an outdoor statistical channel model based on the uniform distribution of the scatterers was proposed.In this model,the canopy of the tree is distributed evenly in the oval area around the mobile station and the base station.The influence of rainfall and snowfall on the signal transmission was analyzed by the relative permittivity of canopy layer in wet environment.Channel parameter estimation results of the model show that the analyses are correct and applicable to macrocell environment,which promotes the research of mobile communication channel model.Secondly,thesis describes some causes of the rain attenuation of the Ka-band communication which may affect the quality of satellite communication and also focuses on the impact of rainfall on the Ka-band communication.Five models which were used to predict rainfall attenuation are compared with the observed values of Yangtze River delta.By calculating the value of cumulative distribution function,mean value,root mean square and standard deviation in the time range of 0.01%?1%to choose a prediction model which is suitable for Yangtze River delta.In addition,we also analyze the effects of rainfall rate,elevation,elevation angle and frequency on the rainfall attenuation in this area.Last but not least,according to the previous theoretical results and the regional characteristics of the Yangtze River Delta,a suitable 12-multi-beam power distribution program of the Yangtze River Delta is proposed.The simulation shows that this program is an effective method to compensate the rain attenuation in this area.