  In this paper, the performance of a cooperative relaying technique in a
non-orthogonal multiple access (NOMA) system, briefly named cooperative NOMA
(C-NOMA), is considered in short packet communications with finite blocklength
(FBL) codes. We examine the performance of a decode-and-forward (DF) relaying
along with selection combining (SC) and maximum ratio combining (MRC)
strategies at the receiver. Our goal is user clustering based on C-NOMA to
maximize fair throughput in a DL-NOMA scenario. In each cluster, the user with
a stronger channel (strong user) acts as a relay for the other one (weak user),
and optimal power and blocklength are allocated to achieve max-min throughput.
