Self-organized resource allocation based on CSI overhearing in heterogeneous networks employing cell range expansion

In this paper, we propose a self-organized resource allocation method in a macrocell/picocell heterogeneous network employing Cell Range Expansion (CRE). To protect expanded Pico User Equipments (ePUEs) from severe Macro Base Station (MBS) interference in downlink, in the conventional method, MBS makes use of reduced power Almost Blank Subframes (ABSs) where ePUEs can be scheduled. However, this severely limits the amount of usable resources/power for the MBS. In the proposed scheme, MBS predicts the ePUE´s Resource Block (RB) allocation based on their overheard Channel State Information (CSI) feedback intended to Pico Base Station (PBS), and reduces its transmit power in RBs where ePUE´s allocation probability is estimated to be high for mitigating downlink interference. The simulation results show that the proposed scheme outperforms the conventional reduced power ABS scheme in terms of total sum throughput as well as fairness among all heterogeneous users.1