Improving eICIC with coordinated beamforming and scheduling in co-channel HetNets

The choice of coordinated transmission schemes is inherently present in the optimization of future heterogeneous networks (HetNets). Specially, in downlink co-channel HetNets it is necessary to rely on coordination because of the inter-cell interference (ICI). Here we propose an integration of enhanced inter cell interference coordination (eICIC) and coordinated multi point (CoMP) schemes with coordinated beamforming and scheduling. Our approach jointly optimizes the user (UE) selection and transmission in the CoMP-cluster with the aim of maximizing the weighted sum rate within the cluster. We propose and compare two beamforming configurations where signal to leakage plus noise ratio (SLNR) beamforming is applied either by all the base stations (BSs) or only by the macro BSs. We assess the two schemes in terms of a) achievable rates and b) feedback overhead. Numerical results show that the proposed solution outperforms the baseline eICIC by providing a gain up to 55% in the fifth percentile of the UE rate.