Transmit Diversity at the Cell Border Using Smart Base Stations

We address the problems at the most critical area in a cellular multicarrier code division multiple access (MC-CDMA) network, namely, the cell border. At a mobile terminal the diversity can be increased by using transmit diversity techniques such as cyclic delay diversity (CDD) and space-time coding like Alamouti. We transfer these transmit diversity techniques to a cellular environment. Therefore, the performance is enhanced at the cell border, intercellular interference is avoided, and soft handover procedures are simplified all together. By this, macrodiversity concepts are exchanged by transmit diversity concepts. These concepts also shift parts of the complexity from the mobile terminal to smart base stations.