Partial Non-Orthogonal Multiple Access (P-NOMA)

In this letter, we propose a novel hybrid type of power-domain non-orthogonal multiple access (NOMA) in downlink environments, called partial NOMA (P-NOMA). In conventional NOMA, where the signals of user equipments (UEs) are fully overlapped, the utilization of the bandwidth can be maximized, but doing so also maximizes the interference from the other UEs. P-NOMA partially overlaps the UEs' signals by controlling the extent of the overlap and can thus reduce the interference from other UEs. To verify whether this is a possibility with P-NOMA, we observed the performance tendency of the achievable rate versus the overlap ratio and then confirmed that there is an overlap ratio that achieves performance that is better than that of conventional NOMA with respect to the sum of the achievable rate. In other words, slightly reducing the overlap ratio improves the sum of the achievable rate compared to the full overlap ratio.