Transmit Diversity at the Cell Border Using Smart Base Stations

The authors 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. The authors 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, macro-diversity concepts are exchanged by transmits diversity concepts. These concepts also shift parts of the complexity from the mobile terminal to smart base stations.