A Review of Network Massive MIMO and Cell Free Massive MIMO for 5G and B5G

In this paper, a Massive Multiple-Input Multiple-Output (MIMO) topology which is the most fascinating wireless access technique for 5G and beyond networks was studied. Massive MIMO is a branch of MIMO technology that entails attaching hundreds or even thousands of antennas to a base station to enhance spectral efficiency and throughput. The cell-free massive MIMO can give higher spectral efficiency, higher macro-diversity, and lower route loss by placing many service antennas near to the MUs. Imagine a coverage area where, instead of establishing independent cells, each mobile device spectral efficiency, higher macro-diversity, and lower route loss by placing many service antennas near to the Mus. This successfully results in a user-centric post-cellular network design, which can eliminate many of the cellular network's interference difficulties and service-quality inconsistencies.