Spaceborne Systems Research And Design Of The Pn Code Ranging

Since the concept of microsatellite was proposed in the 80's of 20 centuries, its techniques have made great processs in recent years, the development of the microsatellite is a significant trend in the aerospace area. The feature of microsatellite includes light weight, good performance, short development cycle and low cost. As an important part of microsatellite, the TT&C Transponder system should have the feature of simple configureation, light weight, long working time and high reliability. In this thesis, the methods of Digital Pseudo Ranging System in the TT&C Transponder will be systematically studied and validated experimentally.This thesis focused on the design of Digital Pseudo Ranging System and TT&C Transponder baseband hardware flatform and its verification experiments. The architecture of the hardware platform consists of DSP, FPGA, ADC, DAC and etc.According to the theory of regenerative pseudo code ranging, this thesis constructs a digital pseudo ranging system framework and designs code-generation, DTTT, downlink-transmitting module. And all of module will be implemented with VerilogHDL, simulated and verified in QuartusII development environment. The function is verified by simulation, precision experiment, long-distance experiment and WLANwireless experiment. The procedure is that the code-generation module generates pseudo code sequence, then it is sent to DTTL. And DTTL recovers the pseudo codes and the corresponding clock code, and regenerates pseudo code sequence. Lastly it is transmitted to the receiver. Besides the technique of DSP, measures the Phase Contrast of the original signal and the rebirthed signal to get the reality data. Finally, a project of Digital Pseudo Ranging System for the pico-satellite is designed and verified on the experimental platform, which is specially designed.