  This letter proposes the usage of orbital angular momentum (OAM) for
cooperative non-orthogonal multiple access (CNOMA) to enhance sum capacity (SC)
for the future cellular communication system. The proposed CNOMA-OAM scheme is
analyzed and compared with other schemes, i.e., conventional CNOMA,
conventional orthogonal multiple access (OMA) with OAM. The impact of the power
allocation factor for OAM beam over SC is also analyzed. The analytical result
is justified by simulation results which demonstrate that the proposed
CNOMA-OAM provides higher SC compared to other schemes.
