Fluid Antenna-Aided Semi-Full-Duplex System With Non-Orthogonal Multiple Access

Rate balancing becomes challenging with a relatively high downlink signal-to-noise ratio, particularly in achieving symmetric downlink and uplink rates. The semi-full-duplex (SFD) approach, which borrows downlink rate, provides improved rate balancing. However, existing work has mainly investigated SFD with a single uplink user. In practice, multiple uplink users should be supported, requiring advanced techniques to enhance transmission rates. This letter introduces a non-orthogonal multiple access (NOMA) system with the fluid antenna (FA) to improve channel gain in SFD, and investigates the optimization of total uplink rate through FA port selection and time allocation. The results demonstrate that our proposed system achieves better rate balancing.