Document Type : Research Paper
1 Department of Computer Engineering, University of Technology, Baghdad, Iraq Department of Computer Science, College of Science, University of Baghdad, Baghdad, Iraq
2 Department of Electrical Engineering, College of Engineering, University of Baghdad, Baghdad, Iraq
3 Department of Computer Engineering, University of Technology, Baghdad, Iraq
Massive Multiple-Input Multiple-Output (MIMO) is an extension of the conventional MIMO in the wireless systems which improves both of the access density and the spectral efficiency by adding a massive number of antenna array at the base station (BS). Massive MIMO increases the spectral efficiency by using the beamforming. Besides, the beamforming in massive MIMO improves the energy efficiency by focusing the energy in the desired direction instead of the omnidirectional propagation. In this paper, we propose and discuss different beamforming objectives in both the uplink and the downlink channels. These proposed objectives can be either use the beamforming of the desired signal without nulling the interference or use the beamforming with interference nulling. The beamforming with nulling objectives have better performance than those without nulling but this leads to a higher computational complexity as well. The results of this paper show and compare the performance of these objective including the spectral efficiency and energy efficiency as well as the computational complexity.