Optimal SIC Ordering and Power Allocation in Downlink Multi-Cell NOMA Systems

In this work, we propose a globally optimal joint successive interference cancellation (SIC) ordering and power allocation (JSPA) algorithm for the sum-rate maximization problem in downlink multi-cell non-orthogonal multiple access (NOMA) systems. The proposed is based on exploration of base stations (BSs) consumption, closed-form powers obtained each cell. Although JSPA scales well with larger number users, it still exponential cells. For any suboptimal decoding order, low-complexity near-optimal rate (JRPA) strategy which complete region users exploited. Furthermore, design semi-centralized framework two-tier heterogeneous network such that small-BSs users. Numerical results show JRPA highly outperforms case are enforced to achieve their channel capacity by imposing well-known SIC necessary condition allocation. Moreover, significantly fully distributed framework, where all BSs operate maximum budget. Therefore, centralized algorithms performances good choices cells