  Towards the realization of ultra-reliable low-latency wireless communications
required in critical industrial Internet of Things (IIoT) applications, this
paper presents a new noncoherent and non-orthogonal massive single-input
multiple-output (SIMO) framework, in which a large number of antennas are
deployed to provide high spatial diversity so as to enable ultra-reliable
communications, and noncoherent transmission and non-orthogonal multiple access
techniques are applied to effectively reduce the latency at the physical and
data link layers, respectively. A two-user IIoT system is considered to
elaborate the key design principle of our framework, in which two controlled
nodes (CNs) transmit their data to a common managing node (MN) on the same
time-frequency resource block, and the MN implements the noncoherent maximum
likelihood detector to recover the transmitted symbols of both CNs from the
received sum signal. We analyze the error performance of the considered system
and then minimize the system error probability by jointly designing the
constellations of both CNs. Simulation results show that our design has lower
error probability than existing designs.
