Abstract
One of the effective technologies dealing with the transmission that occurs at the overloaded condition with limited resource and improved spectral efficiency is Non-Orthogonal Multiple Access (NOMA). Multiple-Input Multiple-Output (MIMO) is used for fulfilling the demands of 5G communication systems. Integration of both MIMO and NOMA approaches is also explained in the previous researches for improving the communication. The purpose of NOMA is for utilizing multiple access into power domain for providing channel assignment and power allocation. Thus, optimal power allocation is an important parameter in 5G communication so as to utilize the NOMA systems effectively. Accordingly, this survey presents different techniques in MIMO-NOMA systems. Thus, this review article provides the detailed review of research papers presenting various MIMO-NOMA methodologies. The papers reviewed are classified into following types, namely Pilot based techniques, Pre-coder based techniques, Beam forming based techniques, Sum rate based techniques and Cluster-based techniques. Moreover, an elaborative study and discussion are made by concerning fading channels, antennas utilized, implementation tools and evaluation parameters obtained by various techniques. Eventually, the research gaps and issues of various MIMO-NOMA classification schemes are presented for extending the researchers towards a better contribution of significant MIMO-NOMA systems.