Combining eICIC with coordinated beamforming in downlink heterogeneous networks

One of the key enablers for 5th Generation (5G) networks is the on-demand overlay of co-channel pico cells on homogeneous macro layer. However, the problem of inter-cell interference (ICI) is very challenging in co-channel heterogeneous deployments. Therefore, we propose a combination of enhanced inter cell interference coordination (eICIC) and coordinated beamforming (CB) as an evolutionary step to approach the 5G performance requirements. We refer to this step as enhanced coordinated beamforming (eCB). With the help of system level performance assessment for large cellular networks, we show that eCB achieves higher spectral efficiency than eICIC. We propose different clustering approaches which can be applied to achieve a given target metric. Moreover, we evaluate the impact of the pico-offset value, the macro resource coordination factor and the number of pico cells on the performance of a heterogeneous deployment.