A Generic Framework for Dynamic eICIC Optimization in LTE Heterogeneous Networks

Heterogeneous Networks (HetNets) are seen as an effective solution for improving network capacity, offloading traffic and optimizing coverage. However, the transmit power difference between the introduced low power nodes and the legacy macro cells essentially leads to two challenges: Cell Association and Inter-cell interference management. The above issues can be mitigated through the enhanced Inter Cell Interference Coordination (eICIC) feature introduced in LTE release 10. eICIC involves two techniques: 1-Cell Range Extension (CRE) using Cell Individual Offset (CIO) to offload a set of users to the small cells (SC), and 2-Almost Blank Sub-frames (ABS) patterns to 'protect' SC users from interfering macro eNodeBs (eNBs). In this paper, we propose a dynamic solution performing a joint optimization of both CIO and ABS in order to maximize any predefined network utility function. Simulation results illustrate the important performance gains brought by this joint optimization, especially for cell edge users as their averaged throughput is increased up to 300% of their initial performance.