地面与卫星太赫兹通信高频大气窗口分析

较大的传输路径损耗限制了太赫兹无线通信在大气中的传输距离，要想实现地面与卫星之间太赫兹波的长程传输，必须先找到低衰减的大气透明窗口。本文结合我国大气分布特点，通过大气辐射传输模型工具am（atmospheric model）对大气吸收衰减建模进行分析，从中选定适合我国地面与卫星太赫兹通信的理想地基站点；利用真实大气数据和分层传输理论，计算了地面与卫星之间太赫兹通信的总路径损耗，结合信号发射功率、天线增益、信噪比、噪声功率值和相应的路径衰减阈值，给出了天线增益分别为0～100 dBi时10～15 THz频段内的总可用带宽和大气窗口；通过将高海拔平台作为地面与卫星之间太赫兹通信的中继链路，给出了1～15 THz频段内的可用大气窗口，为我国地面与卫星通信链路的建立、地基站点和通信频段的选取提供了理论和数值参考。

Analysis of high-frequency atmospheric windows for terahertz communication between the ground and the satellite

The large path loss limits the transmission distance of terahertz wireless communication in the atmosphere. To realize long-range transmission of terahertz waves between the ground and the satellite, the first and key step is to find low attenuation atmospheric transparent windows. In this paper, based on the characteristics of atmospheric distribution in China, atmospheric model (am) is used to compute and compare atmospheric absorption attenuation of terahertz waves in two representative cities, and obtain the most ideal ground-based site suitable for terahertz communication between the ground and the satellite in China. Subsequently, by means of real atmospheric data and layered transmission theory, the total path loss of terahertz communication between the ground and the satellite is calculated. Combined with the signal transmit power, antenna gain, Signal-to-Noise Ratio (SNR), noise power and the corresponding path loss threshold, the total usable bandwidth and atmospheric windows in the 10?15 THz frequency band are given. Moreover, by taking the High Altitude Platform as the terahertz communication relay link between the ground and the satellite, the usable atmospheric windows in the 1?15 THz frequency band with antenna gain of 0?100 dBi are given, which provide theoretical and numerical reference for the establishment of ground-satellite communication links and the selection of ground-based sites and communication frequency bands in China.