Study On Space-Time Block Coding In MIMO System

With the development of multimedia mobile communication, the spectrum resource is getting more and more limited, which become a great threat to the future mobile communication. So it is urgent to develop high efficient coding, modulation and signal processing technique for the purpose of improving the radio spectrum efficiency. Space-time code is a new coding and signal processing method that combine the channel coding and diversity technique. It can greatly improve the information capacity and transmitting rate in wireless communication system, while the band need not be increased. So it can provide much higher spectrum efficiency than the conventional single antenna system. Space-time block code is paid more attention due to its low decoding complexity, and has been accepted by the third generation mobile communication standard. Furthermore, it will become the key technique of the next generation mobile communication.The main research results of this dissertation are as follows:(1) A new space-time spreading block code scheme has been proposed. The new scheme can realize linear decoding as well as insure a high code rate, so the decoding complexity is low. The simulation results show the better performance of the new scheme compared with some existent coding schemes.(2) In order to further improve the code rate of space-time block code, parallel transmit strategy is introduced in this dissertation, and a parallel space-time coding scheme based on four transmit antennas is obtained. Compared with the conventional scheme, the new scheme can improve the code rate without reducing performance. So the spectrum efficiency is improved greatly.(3) A novel space-time block coding scheme is proposed based on constellation rotation and matrix rotation. The new scheme can achieve full diversity and full rate transmitting. Compared with the quasi-orthogonal space-time block code, the complexity of the new code is reduced.