Slow Fluid Antenna Multiple Access with Multiport Receivers

TL;DR

This paper explores how multiport fluid-antenna receivers with multiple RF chains can enhance slow fluid-antenna multiple access performance by optimizing port selection and combining strategies, even with limited RF resources.

Contribution

It introduces a joint design approach for port selection and combining in multiport fluid-antenna receivers, demonstrating significant performance improvements over existing schemes.

Findings

Joint port selection and combining design improves interference reduction.

Multiport receivers outperform single-port schemes in slow-FAMA.

Performance gains are significant even with limited RF chains.

Abstract

We investigate whether equipping fluid-antenna (FA) receivers with multiple ($L>1$) 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.