Bpsk / Dpsk-based Skin Satellite Monitoring And Control Communication System Software Design

The development of micro satellite imposes requirements of lower power, lighter weight, smaller size and higher flexibility on TT&C transponder. The ground station test system of the micro satellite also calls more flexibility. This dissertation sets up the software design of the TT&C transponder and telemetry data demodulator in the background of the Pica-satellite Project in Zhejiang University.This dissertation starts from the model of the digital signal process algorithms, modulation and demodulation algorithm, and presents advanced subcarrier recovery loop, bit synchronization loop, and Auto Gain Control (AGC) algorithm. The theory and MATLAB performance simulation of the algorithms are presented. The simulation results show that the subcarrier recovery loop, bit synchronization loop, and the AGC work well when the Signal-to-Noise Rate (SNR) is up to 6dB.On the base of the modulation and demodulation algorithm, the detail of the software development of the TT&C transponder is also described. The development involves first the software realization of the base communication function and secondly the reliability increase methods of software. These methods including radiation-harden design and communication links guarantee methods, can effectively decrease the destruction of the Single-event upset and guarantee the establishment of communication links. The feature of the design of the TT&C transponder software is that it can make the Pica-satellite complete a certain extent of command and telemetry fucntion as long as the TT&C transponder and power system work.For the ground station test system of pica-satellite telemetry signal, a software demodulator based on virtual instrumental platform, LabVIEW, is studied and developed. The demodulator is realized through the Visual C++ codes embedded in LabVIEW platform, with the data acquired, displayed and stored by LabVIEW. The demodulator first has great flexibility and secondly saves additional test and store instruments.The TT&C transponder software and telemetry demodulator has been separately realized on DSP system and PXI-5122 Digitizer. The function and performance test results prove the effectivity of the design in this dissertation.