Study On The Performance Of STBC-MIMO-OFDM System

With the fast development of mobile communication, high-speed and large-capacity multimedia service transmission is eagerly demanded. However, it has to face the severe challenge of the limitation of frequency and the influence of multi-path fading that are obstacles to further increase channel capacity and traffic quality. This thesis embarks from the environment for mobile communication system, and focuses on the basic theory of MIMO system and STC technology, which comes out two designing rules of STC from the perspective of mathematics. Then, it emphasizes on the Space-time Block Coding(STBC)which is widely used, resulting in the detailed analysis of the principles and performance of the Orthogonal Space-Time Block Coding(OSTBC) and Quasi-Orthogonal Space-Time Block Coding(QOSTBC) as well as the simulation analysis.STBC-MIMO-OFDM systems can synthesis the advantages of three technologies to bring better performance gain. In this thesis, the group transmitting method used in single antenna system has been introduced into STBC-MIMO-OFDM system, which results in the new system that is NSTBC-MIMO-OFDM system. A multi-dimensional diversity, including time,frequency, space and modulation diversities can be achieved by the NSTBC-MIMO-OFDM system. The thesis proves that the proposed NSTBC-MIMO-OFDM systems provide considerable improvement in the bit error performance compared to the STBC-MIMO-OFDM system at the cost of a slightly more complicated system structure from the perspective of theory and simulation.