Studies On Space-Time Block Coding & Decoding Algorithms And Application

Space-time codes is a channel code technology which bases on multi-elements antenna. It can not only satisfy the wireless transform requirements of high frequency efficiency, but also has strong ability to exterminate multi-paths fading. So it can greatly improve the quality of communication services and system capacity under multi-paths fading channel.Orthogonal space-time block codes (OSTBC) is a key technology which suitables for future 3G and beyond3G mobile communication under wireless multi-paths fading channel. It has simply encode&decode algorithm and full diversity. But the code rate is less than one symbol/period when transmit antennas is more than 2 with two dimension modulation. In order to solve this problem, a new quasi-orthogonal space-time block codes (QOSTBC) was constructed. Meantime OSTBC's application in MIMO-OFDM system was also researched. For all work, some conclusions can be summarized as follows:Firstly, the two already existed OSTBC's schemes were analyzed, and a new QOSTBC by using the structure of OSTBC with maximal rates was given. The relative decode algorithm was also designed. All the mentioned schemes' characteristic was analyzed in details and simulated.Secondly, several space-time block codes apply to MIMO-OFDM concatenated system were designed in order to achieve high rate and multi-users rate which can satisfy the requirement in IEEE802.11n. Both decode algorithms were also given. Then the advantages and limitations of the algorithm were analyzed. The simulation results validated the schemes were practical.