  For a massive number of devices, nonorthogonal multiple access (NOMA) has
been recognized as a promising technology for improving the spectral efficiency
compared to orthogonal multiple access (OMA). However, it is difficult for a
base station (BS) to provide all of the information about NOMA signals via a
high layer owing to signaling overhead concerns. This paper studies blind
signal classification, which determines whether or not the received NOMA signal
requires successive interference cancellation (SIC) without a priori signal
information. In this paper, two types of blind signal classification errors are
analyzed: 1) the signal is classified as one that does not require SIC on the
SIC user side and 2) the signal is classified as one for which SIC is necessary
on the non-SIC user side. In addition, we formulate the joint optimization
problem for user scheduling and power allocation, which maximizes the sum-rate
gain of NOMA over OMA with constraints on the maximum classification error
probability and minimum data rate. The proposed algorithm iteratively finds
solutions for user scheduling and power allocation. Simulation results show
that the proposed scheme outperforms existing user scheduling methods.
