Optimized beamforming for multiuser massive MIMO 6G wireless networks

This paper proposes a number of beamforming schemes for a sixth generation (6G) themed wireless communication system that is comprised of a multiuser, multicell, massive multiple input-multiple output (MIMO) set up with 4, 16, 64 and 128 quadrature amplitude modulation (QAM). The proposed beamforming schemes include, firstly, an adaptive hybrid beamforming scheme that merges the principles of zero-forcing (ZF) and maximum-ratio transmission (MRT) into one MZF scheme. This is the simplest among the proposed schemes, yet, from the results obtained, it offers promising performance trends. Secondly, modified and optimized beamforming versions of the diagonal-block (BD) and the channel-inversion (CI) beamforming schemes are also proposed to check its suitability to massive MIMO systems. Finally, a hybrid CI-BD beamforming scheme that, as the acronym encompasses, combines the idea of BD and CI and takes into consideration the effect of the transmission power and the numbers of antennas is also presented. The purpose of proposing several schemes is to examine the best possible beamforming option that supports adopting massive MIMO technology in 6G systems. Their performance is compared to examine their features against each other and the obtained results show that the proposed techniques possess promising trends in terms of the achievable spectral efficiency (SE) and symbol error rate (SER). From the obtained result it is clear that the adaptive hybrid beamforming scheme outperforms its contender as it is designed to behave adaptively with the channel variations.