With the rapid development of mobile communication systems, multiple access approaches to 5G mobile communications have attracted research attention across the globe. Through this trend various orthogonal and non-orthogonal multiple access techniques have been proposed for 5G systems. This paper focuses on these multiple access techniques. A survey and qualitative comparison are provided to present their limitations vis-à-vis 5G requirements in terms of massive device connectivity levels, data rates, latency features, device costs, energy savings and spectrum efficiency levels. Although the performance of some techniques is well suited to 5G networks, related research must address a number of challenging issues.

orthogonal, non-orthogonal, multiple access, 5G.