基于空间隔离的低轨卫星系统频谱共享方法

随着业务需求的全球性增长，传统低频波段有限的频谱资源已不能满足低轨（LEO）卫星的业务承载要求，采用Ka频段的LEO星座系统设计成为了主流。然而，采用Ka频段的LEO星座系统不可避免地会对同频段已经存在的静止轨道（GEO）卫星系统产生干扰。首先，通过基于空间隔离的干扰规避方法，采用对LEO与GEO的频谱共用系统设置隔离角来进行上下行场景的干扰消除，使该LEO系统能满足国际电信联盟（ITU）对同频段内通信干扰的约束条件；然后，通过引入GEO带的概念，分析并研究了干扰规避区域的确定方法和其对LEO星座密度的影响。最后，通过仿真得出了干扰隔离角、GEO带与LEO星座密度的关系，得到了在采用隔离角的方式进行干扰避让时满足LEO星座系统业务不中断所需要的最小卫星数量，对LEO星座设计具有一定的指导意义。

Spatial isolation methodology for spectral coexistence in LEO satellite systems

The increase demand for global services in recent years has led to the deficiency of resources in traditional low frequency band in low earth orbit (LEO) satellite communication. Thus designs of LEO satellite constellation in Ka band have drawn a lot of interests. However, utilization of Ka band in LEO design inevitably causes interference to the existing geostationary (GEO) satellite system in the same band. A method of the discrimination angle based on spatial isolation in LEO-GEO coexistence systems is adopted to mitigate the interference both in uplink and downlink scenarios and to guarantee that the interference level from LEO system can meet the constraint requirements of communication interference in the same frequency band which are stipulated by International Telecommunication Union (ITU). Furthermore, a concept of GEO band is developed to determine the interference exclusion zone and to research the impact on the LEO satellite constellation density. Finally, simulations of the relationship among the discrimination angle, the GEO band and the LEO constellation density are given and the minimum satellite amount in this method without interrupting satellite services is found, which is significant in LEO satellite constellation design.