Fpga-based Software Monitoring And Control Of Answering Machine Baseband Processor System

In modern aerospace technologies, Pico-satellite is an important research area. With the development of new technology, Pico-satellite not only can achieve effective reductions of satellite size, power consumption and lead time, but also can construct satellite cluster to share resource and information with each other. All these advantages enable them to accomplish more complicated space scientific experiments.With the development of LSI and DSP, SDR(Software Defined Radio) has become an important aspect of the communicating system. SDR's flexibility also adapted to telemetry and controlling of satellite. Its digitalization and modularity will especially be of great benefit to the reduction of tiny satellite's volume, weight and power consumption. In the long run, it's an inevitable trend that TT&C(Tracking, Telemetry and Control) transponder becomes more tiny, integrated and standard. SDR will play a more and more important role in the telemetry and controlling device in aerospace field.Against a background of Pico-satellite research and under the guidance of SDR, this thesis researched the base-band processing system of the TT&C transponder on Pico-satellite. It realized DPSK demodulation and range acquisition filter for the satellite on the digital platform, which provided method for digitalization of on-satellite TT&C transponder and laid the foundation for further research of software defined TT&C transponder.The works in this thesis are following:(1) A hardware test platform including a high-performance FPGA chip "Stratix II" and high-speed A/D & D/A converter was constructed for TT&C transponder.(2) A DPSK demodulator with 8 kHz carrier was designed. The differential coherent demodulation module and lowpass filter module was programmed with Verilog HDL. By analyzing the symbol synchronization technology, DPLL was used to accomplish the demodulation-signal's symbol synchronization. The BER of demodulation system has reached below 10^-5.(3) The range acquisition signal on satellite was filtered and transmitted. High-order FIR bandpass filter was designed and optimized, which was realized in FPGA. By controlling the gain of range acquisition signal with different frequency, the demodulation depth requirement for the phase modulator was satisfied. By filtering the range acquisition signal, the noise was restrained, and the precision of range acquisition was improved.