Design of Picocells in Heterogeneous Networks

A novel Pico cell cite selection scheme in heterogeneous networks (HetNet) is proposed in this paper. Unlike traditional deployment of Pico cells, we consider the scenario with Pico cells at the edge instead of under the umbrella of macro cells in HetNet. In the novel scheme, one Pico cell eNodeB (PeNB) with directional antennas is deployed on the border of neighbor macro cells which is equivalent to a combiner of PeNBs to associate MeNBs around. Compared with the traditional scheme, we have proved that the novel Pico cell cite selection performs better in both fairness and efficiency, in terms of coverage area, offload rate, and field strength for both edge users and overall users in Pico cells with fixed system parameters. Meanwhile, performance gains provided by novel Pico cell site selection is also derived with range expansion consideration. Our results show that, compared with the traditional scheme, more than 0.6944% macro cell users are offloaded to Pico cell in the novel scheme and the offload rate is enhanced by 98.4%. Furthermore, the field strength improved by the novel scheme is twice as much as the traditional scheme.