Research And Implementation Of Transfer Frame In Remote Sensing Satellite Image Simulator Based On CCSDS

Satellite image receiver in the ground station is undoubtedly one of the most importantsegments in the remote sensing satellite system, for the satellite images photographed inspace need to be transmitted down to the ground station waiting for processing. Because ofthe expensive cost of space experiments and the inability of asynchronous satellite toprovide full-time stable output signal for the ground station, some experiments, like thesystem debug of satellite receiver or the initial simulation of software algorithm, areimpossible to be real-time processing, which makes the design of space image simulator forspecial satellite be indispensable in the research of satellite receiving system. This article isto design a space image simulator for remote sensing satellite based on some specificapplication.The main work of this article is as follows. Firstly, we designed a system scheme ofsimulator based on PCI Express; the simulator adopted PCI Express interface to read outimage data from host machine, sending camera signal with encoded in stimulation.Secondly, we used XC6VLX240T-1FFG1156mode FPGA of Xilinx Virtex-6series torealize channel encoding up to CCSDS standard in the simulator, including RS encoding,interleaving, scrambling, as well as adding ASM (Attached Synchronization Marker), andthen serially sending transfer frame out. Thirdly, for the difference of clock frequencybetween RS encoding module and scrambling module in FPGA logic, we investigated themethod of multi-asynchronous clock design to solve the problem of data processing inasynchronous clocks, using dual-port RAM to realize interleaving and the transfer of clockdomains.According to lots of simulation and joint debug experiment with receiving circuit, itwas indicated that the satellite image stimulator we designed was able to send encodedframe data correctly. This work laid the foundation of future research on the satellite imagestimulator.