Dpsk Demodulator Software Of The Dsp-based Skin Satellite

Since the concept of microsatellite was proposed in the 80's 20 centuries, its techniques have made great process in recent years, the development of which is a significant trend in the aerospace area. The microsatellite characterized light weight, good performance, short development cycle and low cost. In 1993 the concept of nanosat was established on the 44th international space navigation conference in Austria, some principles of manufacture, power supply, application were also purposed, much experience were building up to today. With the micromation development of the satellite, the requirements are stricter, especially on bulk, weight and power of every function module. In this thesis, we focused our attention on demodulation and digital signal processing (DSP) technique in the DPSK differential detection system used in pico-satellite test and control instructions, mainly from the point of view of software. The method and performance according to the requirements are resolved mostly. As a key section of microsatellite, the microsatellite baseband signal demodulation system should have the feature of simple configuration, light weight, long working time and high reliability. In this paper, the methods of baseband signal demodulation are systematically studied and validated experimentally.This paper describes the principle and realization of demodulation module in pico-satellite communication system. Then detailed discussion is provided in the structure of demodulation scheme based on DSP circuit. After successful design, the demodulator is tested in different conditions. All of the results indicate that the design requirements are met, and it is suitable for the application to pico-satellite communication. So, the analysis and the comparison between digital method and analog method in the Bit Error Rate and temperature drift experiment are also presented. As a result, the analog demodulation system in satellite must be taken place by the digital system. Furthermore, this paper focused on the universal applications of the software and summarized how to develop the single-object software to the multi-object software, which can run in the same hardware platform successfully.