Research On Space-Time Block Codes With Pre-coding Techniques For Two-User MIMO Interference Channels

In the wireless communication system, wireless signals tend to be affected by noise, attenuation and interference, so that the wireless communication has become a challenging work. Wireless multiple-input multiple-output (MIMO:Multiple-Input Multiple-Output) communication system proposed for the development of the concept of wireless communication has played a important role in promoting its development. MIMO system is a kind of spatial diversity techniques, and exploiting diversity gain is also an important measure of diversity techniques. In addition, bit error rate, transmission rate, the model structure and the complexity of the algorithm are quality standards to measure the performance of the wireless communication system. However, in two-user MIMO system in which two users simultaneously transmit signals, one is the desired signal, and the other is interference signal at the receiving end. How to eliminate interference between users to get the full diversity gain in a two-user MIMO system is a hot research topic at present. Joint precoding techniques can be mixed different transmission symbols to improve the spectral efficiency of the wireless communication system. In this thesis, we will take advantage of pre-coding technology to study two-user MIMO space-time block coding scheme. The main points of this thesis are as follows:(1) Studying the basic theory of space-time block coding, and presenting a variety of design principles in different space-time coding scheme, and several different detection schemes.(2) On the basis of space-time block coding theory, the two-user MIMO system was introduced in the pre-coding technique to study the space-time block coding scheme based on the pre-coding technology. In this theory, the signal to be transmitted at the transmitter is pre-treated encoded, then signal is transmitted to the space-time coding on the corner. The two users differ in the design of space-time block coding, i.e. spatially shifted, the packet at the receiver using the zero forcing algorithm and ML detection signal to the received interference cancellation zero forcing algorithm capable of complete inhibition of other user interference. Therefore, the receiver can get the full desired signal.(3) Both theoretical analysis and simulation results show that pre-coded space-time block coding scheme, Pre-coding and space-time block coding can be used simultaneously. This new method can further exploit system coding gain, lower system bit error rate, and get the full diversity gain at the receivers using a group zero-force algorithm. Furthermore, it can also guarantee the communication system coding gain, and enhance the usefulness and reliability of the system.