The Research Of MIMO Transmission In Satellite Communication System

Satellite communication plays a very important role in providing broadband global information services.It has many advantages,such as wide coverage,low construction cost and so on.With the continuous growth of the number of users and the rapid development of society,people's requirements for the quality of communication services are constantly improving.The way to use limited resources to provide reliable services for more users has become a major issue in the communications industry.The main advantages of MIMO technology lie in spatial diversity and spatial multiplexing.It uses uncorrelated multi-antenna channels to transmit multi-channel data to provide the performance of wireless transmission.Therefore,the application of MIMO technology in satellite communication system will further improve the performance of satellite communication system and improve efficiency of transmission.At present how to apply MIMO transmission technology to satellite communication system has become one of the research hotspots at home and abroad.On the basis of studying the principle of satellite MIMO transmission.precoding and multi-user selection scheme,this paper designs the transmission construction scheme of satellite MIMO,establishes the channel model in bad weather,studies the joint optimization of precoding and power allocation algorithm,and improves the user selection algorithm based on QoS.The main work of this paper is as follows:(1)The model of MIMO satellite communication system is studied.This chapter studies and designs the architecture of MIMO satellite communication system,then analyses the characteristics of satellite transmission channel,and further improves the traditional satellite transmission channel model according to the channel conditions in bad weather and carries out simulation analysis.Finally an adaptive transmission mode switching scheme for MIMO satellite is constructed.(2)The precoding scheme for satellite MIMO multi-user communication system is mainly studied and improved.This chapter studies the SLNR maximization precoding algorithm and power allocation part as the basis to minimize interference leakage to other users when sending user data;aiming at this scheme,which does not consider the difference of channel quality among different users,it may produce more leakage interference to users with worse channel quality,and make communication capital between users.The problem of unfair source allocation is further aggravated.A joint optimization scheme of precoding and power allocation based on strict signal-to-noise ratio(SNR)coefficients is proposed and simulated.(3)The multi-user scheduling technology in satellite MIMO multi-user communication system is mainly studied,focusing on the high computational complexity of user and user selection schemes with different QoS requirements because satellite MIMO needs different services,and the optimization of multi-user selection algorithm based on SLNR criterion is studied.The algorithm takes SLNR maximization as criterion according to different industries.The QoS requirements of transaction types use different strategies of user scheduling schemes.Finally,several classical user scheduling schemes and optimized user scheduling schemes are simulated,and the simulation results are analyzed.