Design And Implementation Of Payload Signal Simulation System For Spaceborne Automatic Identification System

Since the 21st century,along with economic globalization,the world’s demand for ocean transportation has continued to increase.The satellite ship automatic identification system is a new type of digital ship information auxiliary system.The AIS system based on satellite relay communication can achieve large-scale coverage in sea areas far away from land,helping marine monitoring agencies to grasp the information of surrounding sea areas in time.The satellite AIS system uses self-organizing time division multiple access technology,coupled with the influence of the satellite’s high-speed operation on the signal,resulting in a series of problems such as signal overlap and loss in the satellite AIS signal.In order to avoid unsatisfactory detection performance of AIS satellites after launch,it is necessary to find a suitable satellite design scheme from a large amount of experimental data.There are few satellite AIS data available in China,so a reliable and accurate satellite AIS payload signal simulation system is needed to provide effective AIS experimental simulation data.Starting from the basic satellite AIS technology,this thesis investigates a large number of relevant technical achievements at home and abroad,and designs and implements a satellite AIS payload signal simulation system platform.First of all,this thesis fully investigates the current status of satellite AIS research,combined with satellite AIS related international standards and recommendations,and studies the related technologies of satellite AIS simulation system.Secondly,this thesis analyzes and points out the shortcomings and shortcomings of the existing AIS simulation system and algorithm.Combining theories of mobile satellite communication and other relevant international standards for satellite AIS systems,this thesis proposes a new dynamic satellite AIS simulation model,introduces the design ideas of the simulation architecture of the satellite AIS simulation system,and elaborates the design and implementation of each module of the system from the two aspects of the simulation source and demodulation ends of the satellite AIS simulation system.Next,in order to further improve the operability and usability of the system,this thesis designs and implements a satellite AIS simulation system visualization platform.This thesis introduces the architecture of the platform,and shows the functional design and use process of each interface of the platform.Finally,this thesis uses scenarios and various satellite parameters as variables,and uses the satellite AIS simulation system to conduct simulation experiments,and analyzes the system’s signal conflict multiples and detection probability under different conditions.According to the results of simulation experiments,an optimization scheme of AIS+LAIS simulation system to improve the probability of ship detection is proposed.Synchronous implementation and system simulation on the platform verify the feasibility of the scheme.