Research On Space Satellites Formation Network Topology And Related Technologies Of Its Nodes

Satellite communication has some advantages, such as wide coverage, largecommunication capacity, good transmission quality, quick forming network, andconvenient to realize global seamless link, etc. It is an important way to realizethe communication of globalization and personalization. Therefore, thedevelopment of satellite communication attracted a great deal of attention sincethe20th century. Recently, more and more attention has been paid to the microsatellites. In contrast to the large satellites, it has the advantages of shortpropagation delay and low transmitted power. Tiny satellite with more starsformation networking is gradually becoming a hotspot research object onsatellite communications system. This treatise is supported by the NationalNatural Science Foundation project “space sensors based on large-scaleformation flying microsat constellation network networking Mechanismresearch (NSFC:60902014)”, aiming to do a research on improving a Picosathardware system.First, the paper introduces home and abroad LEO formationsmicrosatellite communication system, researches satellite formation technologyand designs a Flower circular formation network topology model with a centralnode and a triangular network topology model. What’s more, it uses thesimulation of two constellations under the STK, then gets some data like themaximum and minimum distance of ISLs (inter-satellites-links) and thecoverage characteristic of the satellite on the ground.Secondly, according to the development of Pico-Sat technology as well asthe demand for Picosat space missions at present, we make an analysis of thebasic technology of FPGA based on reconfigurable hardware structure anddesign a hardware circuit of Picosat on data loading part. This part includes thedata storage system, the clock unit, the radio transmission unit, the powersystem used for data processing and transmission and video capture system, etc.Besides, it gives the basis for the selection of chip.Then, depending on the pico_satellite formation networking principle, this thesis proposes to apply distributed computing technology to the spacepico_satellite networking, so, the whole networking can work together toachieve the capabilities of a big satellite. Take distributed image compression asexample, this thesis design a distributed image compression algorithms forsensor networks, which based on LBT transform. And then this algorithmverifies that the distributed processing technology is superior centralizedprocessing technology.Finally, according to the shortcomings of the Picosat which has short lifeand should be scrapped after completing task, this thesis proposes to applyreconfigurable computing technology to the hardware system of the Picosat,then it illustrates the development process of reconfigurable technology and itshardware foundation. We carry out dynamically reconfigurable simulationexperiment by using Bitstream technology based on Xilinx Virtex-Ⅱ Proplatform, and get a specific design method of dynamically reconfigurableapplied JBits technology. Finally, we get a conclusion that validation usingreconfigurable technology can greatly improve the reuse of hardware resourcesin Picosat and pick up the processing speed of the hardware.