3GPP eICIC: Configuring Almost Blank Subframe Duty Cycles and Load Balancing in HetNets

This paper proposes a method to compute the macrocell almost blank subframe duty cycles, so that the performance of macrocell users in a scenario with expanded-region picocells is the same or controllably larger than the performance of macrocell users in a scenario without range expansion. Moreover, in order to make the most of the macrocell almost blank subframes, this paper also proposes a local load balancing algorithm in which each pico Base Station (BS) at a regular basis performs a local load balanced scheduling to equalise the performance of the two worst picocell users scheduled in subframes overlapping and non-overlapping with macrocell almost blank subframes. These two features together provide a more efficient offloading in HetNet scenarios with controlled MUE performance and better use of resources. System-level simulation results show that compared to cutting-edge techniques, the load balancing algorithm can provide a 37% 5%-tile and 20%mean pico cell throughput enhancement, while the proposed method to compute ABS duty cycle can achieve a 17% mean pico cell throughput improvement.