Differential STBC for OFDM based Wireless Systems
Benigno Rodríguez Díaz
Broadband wireless mobile data networks are an extremely important technical topic nowadays. These networks are probably the most convenient alternative for achieving the objective of providing and increasing connectivity and Internet access. For underdeveloped countries, these networks are an excellent alternative to diminish the so-called digital gap. For developed countries, they represent an opportunity to increase services, security and comfort.
Broadband wireless networks have been studied, considering their component modules, algorithms and also possibilities of interaction between them. This study was necessary to compare different technical alternatives and earn some knowledge about the related advantages and disadvantages. From this study the dominance of the Orthogonal Frequency Division Multiplexing ( O F D M) transmission techniques became clear. It was also clear that multiple antenna ( M I M O) systems are needed to guarantee high data rate transmission schemes. The combination between the O F D M transmission technique and multiple antenna M I M O systems is the key focus of this thesis. Robustness and bandwidth efficiency of new differential transmission techniques, improved by the use of diversities, in particular spatial diversity and the related advantages have been studied. Then the attention was focused in these areas, O F D M transmission technique in combination with a subcarrier wise processed differential and spatial diversity technique.