On the Performance of Opportunistic NOMA in Downlink CoMP Networks

In this letter, an opportunistic NOMA (ONOMA) scheme is proposed in a coordinated multipoint (CoMP) system. Compared with the conventional joint-transmission (JT) NOMA in CoMP, the main purpose of the ONOMA scheme is to advance the capability of the CoMP system and the effectiveness of the successive-interference-cancellation (SIC) decoding process. The relationship between the topology of the ONOMA cells and the sum-rate of CoMP network is analyzed. Meanwhile, the outage probability of ONOMA system is derived and evaluated in an ideal case and nonideal case, respectively. In the numerical results, the sum-rate and the outage performance of the proposed ONOMA CoMP are compared with the JT-NOMA CoMP and it is shown that the proposed ONOMA scheme outperforms the conventional JT-NOMA scheme in CoMP system.