Full Duplex Assisted Inter-cell Interference Cancellation in Heterogeneous Networks

TL;DR

This paper introduces a novel full duplex assisted inter-cell interference cancellation scheme for heterogeneous networks, enabling pico base stations to independently suppress cross-tier interference without involving the macro base station.

Contribution

The paper proposes a full duplex based ICI cancellation method at pico base stations, providing a new approach that operates independently of macro base station coordination.

Findings

Closed-form optimal fICIC solution for single-user case

Asymptotic performance analysis in ICI-dominated scenarios

Enhanced interference mitigation demonstrated through simulations

Abstract

The paper studies the suppression of cross-tier inter-cell interference (ICI) generated by a macro base station (MBS) to pico user equipments (PUEs) in heterogeneous networks (HetNets). Different from existing ICI avoidance schemes such as enhanced ICI cancellation (eICIC) and coordinated beamforming, which generally operate at the MBS, we propose a full duplex (FD) assisted ICI cancellation (fICIC) scheme, which can operate at each pico BS (PBS) individually and is transparent to the MBS. The basic idea of the fICIC is to apply FD technique at the PBS such that the PBS can send the desired signals and forward the listened cross-tier ICI simultaneously to PUEs. We first consider the narrowband single-user case, where the MBS serves a single macro UE and each PBS serves a single PUE. We obtain the closed-form solution of the optimal fICIC scheme, and analyze its asymptotical performance in ICI-dominated scenario. We then investigate the general narrowband multi-user case, where both MBS and PBSs serve multiple UEs. We devise a low-complexity algorithm to optimize the fICIC aimed at maximizing the downlink sum rate of the PUEs subject to user fairness constraint. Finally, the generalization of the fICIC to wideband systems is investigated. Simulations validate the analytical results and demonstrate the advantages of the fICIC on mitigating cross-tier ICI.