Research On MIMO Space-Time Coding And Channel Capacity In Modern Satellite Systems

This thesis mainly studies the application of MIMO technology in satellite mobile communication system and the performance analysis of and space-time coding technology.With the continuous progress of science and technology,information transmission is also developing rapidly,accompanied by the shortage of spectrum resources.Under the condition of increasingly serious satellite orbital space constraints,how to effectively expand capacity,improve transmission capacity and spectrum utilization has become an urgent problem to be solved in the industry.Establishing the model as accurately as possible is an important basis for further in-depth study of various parameters.In order to truly reflect the multipath and masking in the signal transmission,this paper establishes a multi-state land mobile satellite channel model with the help of Markov chain,and further studies the parameters affecting the channel capacity,including antenna,channel terminal height angle and so on.Through simulation analysis and comparison of Rayleigh's new characteristics and influencing factors,it is shown that improving the encoding and decoding performance of space-time block codes and space-time trellis codes can be achieved by diversity order.Finally,aiming at MIMO land mobile satellite communication channel,this paper will study and judge which factors will affect the BER performance of the coding system channel.After carefully exploring the data and relationship,it can be concluded that the performance of space-time trellis code is better than space-time block code in most different cases;In the land mobile satellite channel,regardless of the environmental factors,the satellite altitude angle increases continuously,and other conditions remain unchanged,the bit error rate of STBC and STTC decreases,and the decline speed of STBC is faster.