A CDMA mixed cellular architecture with space division duplex (SDD) for symmetric/asymmetric wireless communications

We explore the use of a novel duplex scheme-space division duplex (SDD) in a CDMA mixed cellular architecture for supporting symmetric data services and asymmetric data services with the former served by FDD regular cells and the latter served by SDD picocells (System I). Using per-cell capacity as our measure, the performance of System I is evaluated and compared with two other approaches (System II and III) in which System II utilizes FDD in both regular cells and picocells and System III simply utilizes FDD in a regular cellular architecture to serve both symmetric and asymmetric data users.