Improving eICIC with CoMP-CB/CS in Downlink Heterogeneous Networks

The deployment of small and pico base stations (BSs) represents an important solution to meet the rate requirements of 5th generation (5G) networks. On the other hand, the achievable rates in heterogeneous networks (HetNets), where different types of base stations with different power capabilities share the same bandwidth, are limited by inter-cell interference (ICI). Here, we propose an integration of enhanced inter cell interference coordination (eICIC) and coordinated multi point (CoMP) schemes to manage the ICI in downlink HetNets. We focus on CoMP with coordinated beamforming (CB) and scheduling (CS), where the BSs of a cluster share only the channel state information (CSI) to jointly schedule the UEs and design the precoders. First, we assume that all the BSs of the cluster use signal to leakage plus noise ratio (SLNR beamforming to mitigate the intra-cluster interference. Then, as in HetNets macro BSs are the dominant interferers, we propose a more simple solution where only the macro BSs use SLNR beamforming. The benefits of the proposed schemes are evaluated in terms of a) achievable rates by using system simulations and b) feedback load.