Based Dsp Leather Satellite Differential Demodulator

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. Main contents as follows:(1) According to the demodulation guideline, a differential detection system is applied to the DPSK signal demodulator, which is based on the analysis and comparison using the principle of optimal binary signal detection. Moreover, the demodulation is simulated with Matlab to ensure the essential conditions for the detection system to run normally.(2) A simple and general hardware stage is built, on which the DPSK signal will be differentially demodulated and processed. This system is realized in the way of software radio and mainly based on the DSP circuit, which includes a CPLD chip to control the logic and time sequence. At the same time, the whole system achieves its minimum bulk, weight and power because of the excellent performance of these chips.(3) In the FIR digital filter design, the optimal consistent approach and Matlab simulation is adopted. As to symbol synchronization, a simple but effective flow is discussed and analyzed penetratingly. At last, the working flow of the whole system is designed. The division of function modules and their flow design are also achieved successfully.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.