Research Of The Key Technology For Ground Station Simulator Of TT&C Transponder Based On Embedded System

The ground station system for satellite tracking and measurement is complex,with a long cycle and expensive.In order to test this TT&C in the laboratory,a set of analog ground station with reasonable prices is needed.Based on the above facts,this paper takes the satellite research project of China-Europe cooperation as the background,and responds to the ground station as the research object.the paper designs a ground station system with a simple “PC+FPGA+RF integrated chip” architecture,breakthroughs key technologies.The main work in this paper are finished as the following aspects.1.Realizing the data communication between the host computer and the FPGA.The MicroBlaze soft core processor is used as the core to complete the construction of the hardware platform circuit including UART,interrupt controller,Ethernet interface,external memory,timer and other peripherals;Using the TCP protocol,transplanting the embedded LWIP protocol stack completes the transmission of remote control and telemetry data.2.Transplanting the software project provided by ADI to complete the configuration of the RF integrated AD9364 chip.which avoids the process of configuring thousands of registers in the traditional method and reduces the configuration work.3.Completing the design of the ground station simulator upstream modulation module and generating telecontrol signal,precision frequency side tone signal,sweep signal for detecting the performance of the USB TT&C.The logic circuit module in the FPGA mainly includes: an accurate frequency side tone sequence generation circuit,a side tone wheel generation circuit,a remote control subcarrier generation circuit,a BPSK+PM secondary modulation circuit,and a frequency sweep circuit.The performance of each circuit module is tested through the Chipscope and the spectrum,and the results meet design expectations.4.Introducing the demodulation algorithm of ground stations in detail.The performance of the demodulation algorithm is simulated through the Simulink platform,and the results prove the correctness of the demodulation algorithm.