Design Of Intra-satellite Wireless Infrared Optical Communication System

Satellites are internally loaded with various loads,remote terminals,interface units and on-board computers;the data transmission between them is mainly achieved through wired communication cables.The large number of communication cables brings not only the increase of the volume and weight of the satellites,resulting in a decrease in the proportion of payload,but also increasing the difficulty of the assembly,integration and testing phases in the ground.Intra-satellite wireless optical communication technology uses wireless light instead of traditional wired communication cables to complete the data communication in the satellite,which can effectively solve these problems and become a hot topic in recent years.This project focuses on the research of intra satellite wireless optical communication technology,designs and tests the intra satellite wireless optical communication system.This paper first introduces the research progress of intra-satellite wireless optical communications and ground-based wireless communication in small space.Then,The key technologies of Intra-satellite wireless optical communication were researched.and the diffuse reflection optical link channels in the intra-satellite space are analyzed.The intensity distribution and multi-path delay of the intra-satellite simulation space are simulated in Tracepro.The advantages and disadvantages of each modulation scheme in wireless optical communication and theirs impact on the communication system are compared and analyzed.Based on the features of high reliability,the non-strict definition of the transmission medium,and the ability to support real-time control of multi-host distribution,the CAN bus is used in the intra-satellite wireless optical communication system.The characteristics of the stability,bandwidth,noise characteristics,and signal-to-noise ratio of the system were analyzed and simulated in Pspice,the simulation results are consistent with the theoretical analysis.The relevant conclusions of the simulation analysis can guide the device selection and circuit design of the transceiver circuit.Infrared transceiver circuit module is designed to replace the transceiver module in traditional CAN bus communication,and the hardware and software design of CAN communication module is completed.Finally,a CAN communication system based on wireless light is built,and data communication based on CAN protocol is implemented.At the end of the study stage,a satellite simulation platform was set up.The diffuse reflection infrared wireless optical communication system was tested on the simulation platform.The experiment of diffuse reflection wireless optical communication was successful in most place of the simulation platform space.The main innovation of this paper:(1)Starting from the application requirements and characteristics of the communication system,a detailed analysis and simulation of the diffuse reflection optical link in the intra-satellite space and the electrical characteristics of the system are carried out,and a theoretical model of the light-diffuse reflection communication link is proposed.(2)The overall scheme of the on-board wireless communication system based on the CAN bus protocol is proposed,detailed software and hardware design as well as communication performance simulation analysis are performed.(3)The experimental prototype was developed and the communication speed achieved 1Mbps.The feasibility of the system scheme was verified.