  Non-orthogonal multiple access (NoMA) as an efficient way of radio resource
sharing can root back to the network information theory. For generations of
wireless communication systems design, orthogonal multiple access (OMA) schemes
in time, frequency, or code domain have been the main choices due to the
limited processing capability in the transceiver hardware, as well as the
modest traffic demands in both latency and connectivity. However, for the next
generation radio systems, given its vision to connect everything and the much
evolved hardware capability, NoMA has been identified as a promising technology
to help achieve all the targets in system capacity, user connectivity, and
service latency. This article will provide a systematic overview of the
state-of-the-art design of the NoMA transmission based on a unified transceiver
design framework, the related standardization progress, and some promising use
cases in future cellular networks, based on which the interested researchers
can get a quick start in this area.
