摘要
为了定量分析非静止轨道卫星信道的多普勒频移特性 ,引入一种基于地心固连坐标系的分析模型 ,经近似 ,该模型与地面接收终端的地理坐标无关 .计算出了几种典型非静止轨道卫星信道的最大多普勒频移 .分析表明 ,高仰角状态下信道中的多普勒频移较弱 ,而处于可视仰角状态时信道中的多普勒频移最大 .应尽可能在高仰角状态下接收信号 ,并可将多普勒时变规律作为先验信息用于对多普勒频移进行估计与补偿 。
An analysis model based on the earth centered fixed coordinate frame is introduced, for achieving a quantitative analysis of Doppler shift characteristics over non-GEO satellite channels. The model is irrelative to the geographical coordinate of receiving terminals on the ground after approximative processing. The maximum Doppler shift in some typical non-GEO satellite channels are figured out. It is concluded that Doppler shift is weaker in the high elevation angle state, and is maximal in the visible elevation angle state. As a result signals should be received at the high elevation angle. In order to weaken the impact of the time-selective fading, the Doppler-time regulation as a prior knowledge can be used for estimating and compensating the Doppler shift in channels.
出处
《北京理工大学学报》
EI
CAS
CSCD
北大核心
2005年第2期143-146,共4页
Transactions of Beijing Institute of Technology
