Interference Mitigation Based on Partial CSI Feedback and Overhearing in an OFDMA Heterogeneous System

We consider the problem of femtocell/macrocell interference mitigation in an OFDMA based Downlink (DL) heterogeneous system. Most conventional methods rely on the information of the interference channel states and Macrocell User (MU) allocation provided by a control channel, causing large overhead increase. In our proposed method, each Femtocell Base Station (FBS) is able to predict the subchannel allocation of MUs based on partial Channel State Information (CSI) feedback and overhearing from the MUs to the Macrocell Base Station (MBS). Based on this estimation, each FBS performs subchannel and power allocation to Femtocell Users (FUs). With this procedure, the proposed method achieves excellent MU/FU sum-rate while greatly reducing required overhead compared to reference schemes.