  This letter proposes a simple design of intelligent reflecting surface (IRS)
assisted non-orthogonal multiple access (NOMA) transmission, which can ensure
that more users are served on each orthogonal spatial direction than spatial
division multiple access (SDMA). In particular, by employing IRS, the
directions of users' channel vectors can be effectively aligned, which
facilitates the implementation of NOMA. Both analytical and simulation results
are provided to demonstrate the performance of the proposed IRS-NOMA scheme and
also study the impact of hardware impairments on IRS-NOMA.
