Slow Fluid Antenna Multiple Access With Multiport Receivers

Abstract

We investigate whether equipping fluid-antenna (FA) receivers with multiple ( ${L}~\gt 1$ ) radiofrequency (RF) chains can improve the performance of the slow fluid-antenna multiple access (FAMA) technique, which enables open-loop connectivity with channel state information (CSI) available only at the receiver side. We analyze the case of slow-FAMA users equipped with multiport receivers, so that $L$ ports of the FA are selected and combined to reduce interference. We show that a joint design of the port selection matrix and the combining vector at each receiver yields significant performance gains over reference schemes, demonstrating the potential of multiport reception in FA systems with a limited number of RF chains.