Digital Satellite QPSK Demodulator Theoretical Research And Engineering Implemention

With the further development of satellite communications, communication satellites from the last century, the development of transparent to the signal processing type, and from the development of a single satellite to space satellite network. Demodulator technology to achieve these changes is not only one of the core technology, but also further enhance the ability of satellite communications of great significance. Same time, because the characteristics of satellites, so that the design, manufacture of demodulator on satellite are different from demodulator on ground. So it makes profound significance to choose the engineering research of digital demodulator on satellite as my subject of academic dissertation.In this paper, plenty of research on demodulation technology and implementation has been done based on digital demodulation used in satellite. The paper first compare the present structures of the various demodulators, and propose a optimal structure scheme used in satellite demodulator. Then, the clock synchronization and carrier synchronization have been deeply studied. Through the system simulation results, it show that the demodulator can be a good lock. Finally, satellite project is put forward to understand the software demodulator implementation and hardware implementation, and a variety of environment tests on the demodulator show that the demodulator meet the requirements.