Adaptive precoding for femtocell interference mitigation

Ahmed R. Elsherif, Ahmed Ahmedin, Zhi Ding, Xin Liu

Abstract: In this paper <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> , we study interference mitigation in cellular networks with femtocells. We propose to use adaptive distributed beamforming to mitigate downlink interference between femtocell users, known as Home User Equipments (HUEs), and macrocell users, known as Macrocell User Equipments (MUEs). We develop three MEVIO beamforming schemes for interference mitigation that take into account the QoS requirement of femtocell and macrocell clients. These new heterogeneous MIMO precoding strategies improve flexibility in resource provisioning and signaling requirement in response to QoS need. The proposed schemes minimize the interference at the MUE or maximize the throughput at the HUE depending on the network traffic and QoS constraints. We also analyze the MUE mean throughput by applying order statistics theory.