Embedded Software Design And Implementation For Satellite-borne Quantum Communication Experiment System

Quantum communication is an emerging cross-field discipline formed by information science and quantumtheory, it is the forefront of research of the field of communication and information. With the development ofquantum computer technology, classical cryptography system is facing more attack, and the study of quantumcommunication which aims at the future has become increasingly important. Currently, fiber-based quantumcommunication technology has become more sophisticated, but because of the loss of the fiber, the distance ofquantum communication is limited. Because of the transmission loss in outer space is almost zero, the proposedconcepts of global quantum communications network will have an unlimited effect on the future development ofcommunication. The satellite-to-ground quantum key distribution which is based on space platform can connectthe multiple fiber quantum communication networks on the ground, so it can really achieve the wide-area’squantum communication network. Therefore, the study of satellite borne quantum communication experimentsystemisbecominga hottopicfromvariouscountries.This topic is part of satellite borne quantum communication experiment. The PowerPC405hard coreembedded in Xilinx’s Virtex-II Pro family’s PFGA chip was used to build the overall structure of quantumcommunication system embedded software. Four modules which included instruction processing module,quantum communication control module, science data interactive module, data post-processing module weredesigned based on RS422interface, quantum communication control circuit, LVDS interface and the quantumkey’s extraction principle. We carried out the instruction’s receiving and transmitting through the RS422bus,completed the communication control by the hardware driver design, did the high-speed science data transmissionbetween the system and control center, at last, we achieved the quantum key’s extraction algorithm by theinteractiveinformation.We used hammingerrorcorrectionmethod,it considered theerrorcorrectionperformance,andreducedthe numberofinteractions.Currently, the system has successfully completed a number of validation experiments, including the localindoor quantum key distribution experiment and the outdoor long-distance quantum key distribution experiment.After experimental tests, the system is proved to be stable, reliable, and it can achieve the quantum keydistributionexperimentwellbetweenthe satelliteandtheground.