Selective interference alignment for MIMO femtocell networks

An interference limited multitier multiuser MIMO cellular uplink is considered. Specifically, an interference management scheme is proposed where interference from subsets of macrocell users is aligned at the femtocell base stations in order to ensure acceptable service for the femtocell users. The scheme employs interference alignment (IA) at each femtocell base station (FBS), to the set of macrocell users (MU) that are causing the high interference specifically at that FBS, and hence is termed selective IA. The proposed IA algorithm determines the interference subspaces at each FBS and precoders for each MU in a distributed fashion. Numerical results demonstrate the performance advantage of selective IA.