Enhanced User Grouping and Pairing Schemes for CoMP NOMA based Cellular Networks

Non-orthogonal multiple access (NOMA) has been identified as one of the promising technologies to enhance the spectral efficiency and throughput for the 5G and beyond cellular networks. Alternatively, coordinated multi-point (CoMP) improves the cell edge users coverage. Thus, CoMP and NOMA can be used together to improve the overall coverage and throughput of the cell edge users. However, user grouping and pairing for CoMP-NOMA based cellular networks has not been suitably addressed in the existing literature. Motivated by this, we propose two user grouping and pairing schemes for a CoMP-NOMA based system. Both the schemes are compared in terms of overall throughput and coverage. Numerical results are presented for various densities of users, base stations, and CoMP thresholds. Moreover, the results are compared with the purely OMA-based benchmark system, NOMA only, and CoMP only systems. We show through simulation results that the proposed schemes offer a trade-off between throughput and coverage as compared to a purely NOMA or CoMP based system.