Space-Based Electromagnetic Spectrum Sensing and Situation Awareness

With a booming number of wireless Internet-of-Things devices, satellite communications have been recognized as a key pillar to support massive communication and ubiquitous connectivity in sixth-generation usage scenarios. In the meanwhile, such expansion of space-terrestrial integrated networks makes satellite radio spectrum management complicated. To facilitate spectrum surveillance and efficiently utilize spectrum resources, space-based electromagnetic spectrum monitoring becomes an urgent demand. This paper first investigates state-of-the-art ground-based spectrum monitoring schemes and satellite spectrum monitoring schemes. As crucial enabling technologies for satellite spectrum monitoring, satellite spectrum sensing and database technologies are systematically outlined, as well as their characteristics and limitations. To tackle with the limitations, this paper proposes a space-based spectrum situational awareness method with spectrum situational maps. By applying generative adversarial networks, the spatial correlation of satellite spectrum data is intrinsically utilized to visualize the distribution of radio spectrum situational information in spatial domain. In addition, challenges in monitoring uplink transmissions with narrow directional beams, as in low-Earth orbit satellite internet, are discussed. To handle this issue, a novel satellite spectrum monitoring scheme is proposed by using reinforcement learning and target probability map. The scheme is also validated by numerical results with a case study.