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 con- sidered. 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/multi- cell processing and different relaying strategies at the femtocells.