In this paper, we address the problem of three dimensional beamforming (3DBF) in millimeter wave (mmWave) wireless networks. In particular, we study the impact of base station (BS) antenna tilt angle optimization on the energy efficiency (EE) of mmWave networks under two different scenarios: a homogeneous network consisting of multiple macro base stations (MBSs), and a heterogeneous network where several femto base stations are added within the coverage areas of the MBSs. First, by adopting a stochastic geometry approach, we analyze the coverage probability of both scenarios that incorporate the 3DBF. Then, we derive the EE of the networks as a function of the MBS antenna tilt angle. Next, optimization problems are formulated to maximize the EE of the networks by optimizing the tilt angle. Since the computational complexity of the optimal solution is very high, near-optimal low-complexity methods are proposed for solving the optimization problems. Simulation results show that in the mmWave networks, the 3DBF technique with optimized tilt angle can considerably improve the EE of the network. Also, the proposed low complexity approach presents a performance close to the optimal solution but with a significant reduced complexity. mmWave network, 3D beamforming, coverage probability, energy efficiency, tilt angle optimization, blockage effect, stochastic geometry, HetNet.
Finally, in REF , the problem of maximizing the energy efficiency of mmWave cellular networks via tilt angle optimization is considered.
Energy Efficiency Maximization in mmWave Wireless Networks with 3D Beamforming
arXiv: Signal Processing
Computer Science Engineering