Design Of Satellite Terrestrial Test Equipment For LEO Spread Spectrum Transponder Based On SDR

Satellite Communication is playing a more and more important role in today'sincreasingly information-oriented society. Its newly emerging applications willcontinue to proliferate in the world.Most of the Satellite TT & C systems are based on USB (Universal S Band) Scheme.Spread Spectrum TT & C Scheme, is an emerging technique used in Satellitecommunications. Compared to USB TT & C Scheme, Spread Spectrum TT & CScheme has its advantages: (1) Convenient for TT & C implementation for severalsatellites in a time; (2) Better anti-jamming performance; (3) Greater telemetrydistance and finer precision; (4) Simplified the whole system. It's considered the nextgeneration of satellite TT & C scheme.In a TT & C system, terrestrial detector of the transponder plays a key role. In thispaper, Software Radio Technology is used to develop a terrestrial detector of SpreadSpectrum TT & C transponder and base band digital signal processing algorithms areimproved.Works of this paper include:(1) Summarize the technology related to TT & C and SDR.(2) Bring out a system design and simulate it.(3) Improve DDC design and lower the calculation complexity.(4) Improve the performance of PLL.(5) Bring forward a new PN code telemetry method which can use digital match filter to realize PN code synchronization.