Uplink interference management techniques for 3G femtocells

In this paper, we present a comprehensive study of uplink interference management for 3G femtocell deployments. Focusing on co-channel deployment, where both femtocells and macrocells operate on the same carrier, femto-to-macro, macro-to-femto and inter-femto uplink interference scenarios are identified. To effectively control uplink interference in residential and enterprise femtocell deployments, Macro Aware noise Rise Setting (MARS) and Controlled LImit on uplink Power (CLIP) algorithms are introduced. MARS maximizes the femto's tolerance to out-of-cell interference by properly setting the femto noise rise threshold based on the location of the femto in the macrocell. CLIP dynamically limits the femto user Tx power or rate to control the interference to macrocell. The effectiveness of the proposed algorithms is demonstrated via detailed system-level simulations for enterprise and residential femtocell deployments.