Читать книгу Spatial Multidimensional Cooperative Transmission Theories And Key Technologies - Lin Bai - Страница 18

The traditional space-based cooperative transmission system is a communication system taking satellite as the forwarding center. Since satellites are usually located at high altitudes away from the ground, space-based systems have incomparable advantages in terms of coverage. Satellite communication systems play an important role in data transmission and global information interaction, especially in maritime, earth observation, and all-weather surveillance. With the increasing demand for bandwidth, service providers and related agencies have to increase the number, bandwidth, and power of satellites. However, the lack of orbital positions for GEO satellites and the lack of available spectrum resources, as well as the increased complexity and increased operating costs caused by power improvements, make these improvements for satellite difficult to achieve. Considering these factors, the space-based cooperative transmission system is proposed to collaborate the multi-coorbital satellites and adopt the technical advantage of multi-antenna systems. Multi-coorbital satellites technology keeps multiple satellites with the same or similar functions in the same orbital position Synchronization and data exchange are achieved through satellite links to form a satellite group with cooperative transmission and forwarding capabilities. Therefore, the utilization rate of satellite orbit resources can be effectively improved, and the deficiencies of single-satellite platform load and power limitation can be compensated. For the multi-antenna technology, by configuring the active antenna array, the coorbital multi-satellites can realize the efficient transmission mechanism of the multi-beam system and obtain the channel capacity gain and also adaptively optimize the transmission mode and improve the energy efficiency according to the continuous change of its structure.