  Recent years have seen proliferation in versatile mobile devices and an
upsurge in the growth of data-consuming application services. Orthogonal
multiple access (OMA) technologies in today's mobile systems fall inefficient
in the presence of such massive connectivity and traffic demands. In this
regards, non-orthogonal multiple access (NOMA) has been advocated by the
research community to embrace unprecedented requirements. Current NOMA designs
have been demonstrated to largely improve conventional system performance in
terms of throughput and latency, while their impact on the end users' perceived
experience has not yet been comprehensively understood. We envision that
quality-of-experience (QoE) awareness is a key pillar for NOMA designs to
fulfill versatile user demands in the 5th generation (5G) wireless
communication systems. This article systematically investigates QoE-aware NOMA
designs that translate the physical-layer benefits of NOMA to the improvement
of users' perceived experience in upper layers. We shed light on design
principles and key challenges in realizing QoE-aware NOMA designs. With these
principles and challenges in mind, we develop a general architecture with a
dynamic network scheduling scheme. We provide some implications for future
QoE-aware NOMA designs by conducting a case study in video streaming
applications.
