Cooperative Hierarchical Cellular Systems in LTE-A Networks

In this paper, we investigate the performance of hierarchical base station cooperation (HBSC) techniques in macrocell/microcell heterogeneous networks for the Third-Generation Partnership Project Long-Term Evolution-Advanced (LTE-A) system. HBSC techniques aim at reducing the cochannel interference between a macrocell and a group of microcells by coordinating the transmissions of distributed antennas in the cell coverage area. We find that joint intra- and intersite cooperation will significantly reduce the intercell interference. Compared with the case without joint intrasite/intersite cooperation, we demonstrate that HBSC in the conventional pentagonal cell architecture can improve spectrum efficiency by 65% at the cell edge. When the narrow-beam trisector cell architecture is considered, the spectrum efficiency can be further improved by 16.42% at the cell edge.