A calibrated intercell interference coordination scheme in heterogeneous networks

Abstract

Many different schemes such as almost blank subframe (ABS) and coordinated multipoint (CoMP) schemes, have been proposed for intercell interference coordination in long term evolution (LTE)-Advanced heterogeneous networks (HetNets). In ABS schemes, high-power cells may transmit almost blank subframes to avoid interference with low-power cell edge users, which will in turn result in reduced high-power cell throughput as cost. Different cells are pushed to cooperate to eliminate intercell interference in CoMP coordinated beamforming, but performance is heavily dependent on the quality of channels and the channel reciprocity. A novel calibrated ABS-CoMP scheme in LTE-Advanced HetNets is proposed, which combines both the ABS and CoMP coordinated beamforming schemes to eliminate intercell interference after channel calibration, and adaptively transmits signals in different ways. It breaks the antenna number constraint of traditional calibration matrix method, and it is assumed to improve system throughput and mitigate signaling overhead and computational complexity. The results from single-picocell to multi-picocell simulations demonstrated that the proposed scheme outperformed the ABS and CoMP schemes in Config.4b scenarios, and achieved considerable system throughput gains.