Cross-tier Interference Mitigation in Wideband HetNets with Full Duplex

Abstract

Full duplex assisted inter-cell interference coordination (fICIC) has been shown effective to mitigate the cross-tier inter-cell interference (ICI) generated by the macro-cell base station (MBS) to the small-cell user equipment (SUE) in downlink narrowband heterogeneous networks. The fICIC applies full duplex technique at the small-cell BS (SBS) such that the SBS can forwarded the overheard ICI to neutralize the ICI directly received at the SUE at the same time as sending the desired signal. In this paper, we develop the framework for the design of wideband fICIC. Different from the narrowband system where only a single-tap forwarding filter is required, in the wideband system the multi-tap time-domain finite impulse response (FIR) forwarding filter needs to be jointly designed with multi-subcarrier frequency-domain power allocation for desired signals. A suboptimal wideband fICIC scheme is proposed in closed form. Simulation results demonstrated the gain of the proposed scheme.