🤖 AI Summary
This work addresses the high hardware complexity and cost associated with conventional multi-port receivers in fluid antenna multiple access systems, which stem from the need for numerous radio frequency (RF) chains. To overcome this challenge, a hybrid multi-port receiver architecture is proposed, leveraging a low-complexity analog beamforming network to decouple port selection from signal combining. By integrating a generalized eigenvector-based port selection algorithm with a tailored stopping criterion, the architecture achieves performance approaching that of fully digital schemes while utilizing only two RF chains. The proposed approach reduces computational overhead by more than 60%, effectively balancing hardware efficiency and receiver performance.
📝 Abstract
We propose a novel receiver architecture that preserves the performance benefits of multiport selection in fluid-antenna systems while requiring only a very small number of radio-frequency (RF) chains. The resulting fluid-antenna hybrid multiport (FAHM) receiver effectively decouples port selection from signal combining by integrating a low-complexity analog combining network similar to those used in conventional hybrid multiantenna designs. We develop a stopping criterion to determine the number of selected ports, which limits the performance loss associated with port selection, and then design the hybrid combiner for a given RF-chain budget. The FAHM architecture is evaluated in a multiuser set-up operating under slow fluid-antenna multiple access (FAMA). In this scenario, a FAHM implementation with only 2 RF chains showcases a performance comparable to a fully-digital conventional multiport scheme with a much larger number of RF chains. Additionally, the proposed receiver architecture attains over 60% reduction in computational burden when integrated with a novel efficient implementation of the state-of-the-art generalized-eigenvector port-selection method.