P-NOMA for Pinching-Antenna Systems (PASS)

Emerging pinching-antenna systems (PASS) introduce new paradigms to construct a strong line-of-sight (LoS) for users by arranging pinching antenna flexibly. Meanwhile, partial non-orthogonal multiple access (P-NOMA) provides novel opportunities to enhance the spectrum efficiency and alleviate the user-interference by means of dynamically controlling the signal overlap ratio between near and far users, further improving the system performance. Thus, this is the first work introducing P-NOMA into PASS, which integrates dynamic signal overlap ratio and flexible pinching antenna architecture to enhance spectral efficiency as well as user fairness. In particular, the sum-rate performance and optimal position of pinching antenna are discussed for LoS and non-line-of-sight (NLoS) scenarios, including orthogonal multiple access (OMA), NOMA and P-NOMA schemes, revealing that the optimal position depends on the transmit power, power allocation coefficients, and dynamic overlap ratio. Moreover, numerical and simulation results are provided to confirm the correctness of our analysis and verify the superiority of our proposed system.