Design And Implementation Of ARQ System Based On Proximity Space Link Protocol

With the rapid development of deep space exploration,the scope of human exploration of the universe is getting further and further,therefore,the requirement of deep space communication technology is getting higher and higher.In deep space communication,it is necessary to ensure the reliability and efficiency of data transmission.This thesis mainly studies the proximity space link communication between spacecraft,analyzes and optimizes the throughput performance and transmission efficiency of the system.The research on general communication systems is used as a basis in this thesis to design and implement a variable window length automatic repeat request system based on CCSDS Proximty-1protocol for data communication of proximity space links in deep space communication.First,a detailed analysis and understanding of the proximity-1 protocol is presented,and the overall scheme of an automatic repeat request system based on the proximity-1 protocol is designed based on the characteristics of the proximity space link communication.Then,a comprehensive comparison of three automatic repeat request schemes is performed.An ARQ scheme for go back N frames is selected.Combined with the proximity-1 protocol,the theoretical analysis and optimization of the transmission frame length and sliding window length are carried out.An automatic repeat request scheme with variable data frame length and sliding window length is then designed.The Visual Studio and Lab Windows/CVI environment are used to design the communication transceiver unit and upper-level interaction unit.Multi-threading,TCP/IP and other key technologies are used to implement the communication status display,data transmission and reception in three working modes,automatic repeat request and performance evaluation.Finally,a semi-physical simulation system for device communication is built in conjunction with the hardware platform for co-simulation,each part of the system design is tested,and the experimental results are analyzed.The experimental results show that the system throughput reach more than 90%under 10^-6bit error rate.Compared with the ARQ system with fixed frame length and window length,the ARQ system with variable frame length and window length achieve a better throughput rate and transmission efficiency.