Joint dynamic point blanking and ABS for ICIC in cloud cooperated heterogeneous network

To mitigate cross-tier interference, almost blank subframe (ABS) has been exploited for heterogeneous networks (HetNet). Macrocells mute or reduce transmission power to avoid interference to picocell edge users. However, the former results in unfairness between macrocells and picocells, and the latter fails to acquire a prominent improvement in energy efficiency (EE). In this paper, a time and frequency domain interference coordination is proposed. Dynamic Point Blanking (DPB) is introduced into ABS scheme to reach a tradeoff between fairness and EE. In time domain, macrocells reduce transmission power during ABSs. In frequency domain, DPB scheme dynamically mutes the strongest interference of coordinated points to further mitigate interference. When the novel DPB is adopted, firstly, the muting pattern is designed to determine DPB users according to coordination. Then a cloud cooperated cellular network (C-HetNet) is introduced, in which small power nodes under a macrocell are connected to cloud radio access network (C-RAN) to operate with the macrocell. C-RAN mutes some macrocells´ resource blocks (RBs) used by DPB users. The simulation results demonstrate that the proposed DPB-ABS scheme can increase the total network EE excellently while ensuring fairness between macrocells and picocells.