Achievable Rates for Multicell Systems With Femtocells and Network MIMO

The uplink of a cellular system where macrocells are overlaid with femtocells is studied. Each femtocell is served by a Home Base Station (HBS) that is connected to the macrocell Base Station (BS) via a last-mile access link, such as DSL or cable followed by the Internet. Decoding at the BSs takes place via either standard single-cell processing or multicell processing (i.e., network MIMO). Closed and open-access femtocells are considered. Achievable per-cell sum-rates are derived in this setting for a linear cellular network. Overall, the analysis lends evidence to the performance advantages of open-access femtocells and sheds light on the performance trade-offs between single/multicell processing and different relaying strategies at the femtocells.