Research On The Performance Of Satellite Cooperative Communication Based On Space-time Coding

Along with the development of the communication technology, satellitecommunication is facing a greater demand of communication service and itsterrestrial terminals tend to have the properties of miniaturization and mobility. Inorder to meet the demand, communication with a larger coverage and capacity isneeded. The reliability and effectiveness of the system can be improved by MIMO(Multiple-Input Multiple-Output) technology, which has been used widely in thefield of the terrestrial mobile communication. But the requirements to the antennaof MIMO technology limit its application in the satellite communication, however,it can be solved by the cooperative communication which can make use of severalsatellites or ground cooperators and make up a virtual MIMO which gains theperformance improvement of the MIMO system. What is more, the coverage areacan be expanded by cooperative communication. Therefore, the cooperativecommunication technology has been selected to the research, with the use of thespace-time coding to improve the performance of the system.Firstly, the domestic and overseas research situation of the satellite cooperativecommunication and the space-time coding as well as the distinction of the satellitecooperative communication system and terrestrial cooperative communicationsystem have been introduced to make the aim of the research clear. Secondly, thechannel model of the satellite cooperative communication system has been built andthe channel capacity of different satellite environments has been estimated. It turnedout that the capacity of the satellite communication system can be upgraded by theuse of the cooperative communication technology in the satellite communicationand the necessity of the research can be seen. Thirdly, the satellite cooperativecommunication system has been researched based on space-time coding and theinfluence of the time delay difference has been taken into account. Because of theparticularity of the satellite cooperative communication system, the system withfixed time delay difference has been researched in Chapter Three and two kinds ofspace-time coding have been selected and contrastive analysis has been done,among which space-time trellis coding and simulated analysis of the influence ofthe parameters to the code have been focused on. The satellite cooperativecommunication system with time varying delay difference has been researched inChapter Four. Based on the basic theory analysis, some delay-tolerated space timetrellis codes have been built. Last, simulated analysis of the performance of thesatellite cooperative communication in different environments has been done. As aconclusion, the use of cooperative communication can make an make an improvement in the satellite communication and the make an improvement ofdifferent space-time codes can achieve different performance enhancements in thesatellite cooperative communication.