ABSF offsetting and optimal resource partitioning for eICIC in LTE-Advanced: Proposal and analysis using a Nash bargaining approach

Almost-blank subframe (ABSF) is a time-domain technique, proposed by the 3GPP to handle Inter-Cell Interference (ICI) in heterogeneous network environments (HetNet). We consider a HetNet environment comprised of a macro-cell and femto-cells distributed across the macro-cell area. We propose a novel approach, called ABSF offsetting, to reduce the blanking rate at the femto-cells while preserving the required optimal blanking rate at the macro-cell. We also study the problem of optimal resource partitioning and offset assignment in the ABSF mode. The proposed solution for the problem is based on multistage Nash bargaining. The performance of the optimal resource partitioning, and ABSF offsetting is evaluated through simulations. The results show that the throughput of the macro-cell is improved, while the degradation in the aggregate femto-cell throughput is reduced due to the reduction in the blanking rate due to offsetting. The simulation results also demonstrate the fairness of the ABSF offsetting with the fairness index approaching 1 among the macro-cell UEs at low loads.