Coverage maximization with switched multi-element antennas in next generation cellular networks

The rapid growth in multimedia services and diverse mobile technologies have recently brought about sudden surges in traffic demands. To keep up with this trend, small cells are considered as a promising solution to supplement macrocell coverage and enhance network capacity in next generation cellular networks. However, the isotropic characteristics of conventional omni-directional antennas installed in small cells reveal a trade-off between coverage and power consumption. Boosted power levels allow for larger coverage areas while resulting in serious interference among cells. On the other hand, although weak power emissions can mitigate interference, coverage holes may appear instead. To overcome the physical limitations, a beamforming technique called switched multi-element antenna (SMEA) is introduced in this work, which is capable of shaping kinds of radiation patterns toward desired users. We propose an efficient radiation pattern selection scheme using SMEA, with the objective of maximizing the total number of served users within the coverage ranges of small cells. We then construct a series of simulations to evaluate the performance of our proposed scheme. Compared with a uniform power control scheme using omnidirectional antenna and a distributed pattern selection scheme using SMEA, simulation results show that our proposed scheme can significantly enhance coverage and deal with the trade-off issue as well. ? 2017 IEEE.