Design Of The Differential Unitary Space-Time Block Codes And Applied In MIMO-OFDM

Space-time coding technology based on Multiple Input Multiple Output (MIMO) ,as the key technology of wireless communications in the future , attracts the most attention and is studied widely, it can takes full advantage of wireless communication multipath channels to improve the anti-fading performance in a communication system, and increase information capacity and transmission rate of wireless communication systems without increasing the bandwidth.MIMO space-time coding technique is a realization form to obtain spatial diversity ,while the space-time block codes become the most important branch in space-time coding technique due to its simple structure , low decoding complexity ,it can significantly increase the reliability of wireless links and improve the performance of the system. At present, most of the research is based on the case of space-time coding when the transmitter and receiver do not need to know the channel state information (Channel State Information CSI), in fact, because the channel is time-varying, it is difficult to obtain timely and accurate channel estimation, so the application of two adjacent time slot signal differential unitary space-time coding and modulation techniques have been proposed asto the optimal design of blind space-time codes. However, the existing method is to combine modulate and the specific signal constellation, when can obtain good performance in circumstances of a high signal to noise ratio only. This page study the differential unitary space-time techniques of quasi-orthogonal space-time block codes ,mainly include:1. Presents and analyzes the traditional differential space-time coding and unitary space-time modulation coding techniques and differential unitary space-time coding techniques.2. Based on the coding scheme of TBH and Jafarkhani, we proposes methods to design a the differential unitary space-time coding matrix base on rotation factor, and proposes four kinds of coding matrix, and applied in MIMO-OFDM system, at the receiving Terminal, simplifies the decoding algorithm in pairs.3. In the conditions of different fading channel, simulated with the MATLAB simulation results verify the inclusion that rotation scheme factor can reduce the error rate.