Beam-nulling based inter cell interference coordination for heterogeneous network

Abstract

In 3rd generation partnership project (3GPP) long term evolution (LTE)-Advanced, heterogeneous network is considered as next generation network topology to improve radio link performance. However, in heterogeneous network, there are various kinds of low power nodes in macro cell's coverage. Since they are sharing the same frequency spectrum, inter cell interference (ICI) is occurred. The main situation that experiences significant performance degradation due to the ICI is the macro user terminal which is close to the femto cell. In this case, the inter cell interference coordination (ICIC) method is necessary to achieve sufficient gain offered by heterogeneous network. Therefore, in this paper, we propose a new ICIC method that femto base station performs called beam-nulling that used position information of interfered user terminal in macro--femto deployment. By using computer simulation and mathematical analysis, we showed that the proposed method not only mitigates ICI but also improves resource utilization efficiency and overall throughput compared to the conventional methods.