Downlink OFDM-FAMA in 5G-NR Systems

2025-01-12

AI Summary

To address low device multiplexing efficiency in 5G downlink under multipath channels, this paper pioneers the deep integration of Fluid Antenna Multiple Access (FAMA) with the OFDM framework, yielding an OFDM-FAMA system fully compatible with 5G-NR channel coding and modulation. We propose a dynamic fluid antenna configuration algorithm based on achievable rates, overcoming the bandwidth adaptation bottleneck of conventional narrowband FAMA in wideband scenarios. By jointly optimizing fluid antenna system (FAS) reconfiguration, multi-user rate allocation, and 5G-NR coding-modulation schemes, the proposed approach significantly enhances multiplexing gain. Under conditions of limited RF chains and robust channel coding, it demonstrably outperforms conventional OFDM systems employing fixed-position antennas (FPA). This work provides the first practical deployment solution and foundational algorithmic support for FAMA in broadband OFDM systems.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Multiagent Systems: Mechanism Design
• Search and Optimization: Sampling/Simulation-based Search

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Experiences and lessons learnt from Web-based algorithms and system deployments
• User Modeling, Personalization and Recommendation: Federated recommendation systems and personalization
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs

Abstract

Fluid antenna multiple access (FAMA), enabled by the fluid antenna system (FAS), offers a new and straightforward solution to massive connectivity. Previous results on FAMA were primarily based on narrowband channels. This paper studies the adoption of FAMA within the fifth-generation (5G) orthogonal frequency division multiplexing (OFDM) framework, referred to as OFDM-FAMA, and evaluate its performance in broadband multipath channels. We first design the OFDM-FAMA system, taking into account 5G channel coding and OFDM modulation. Then the system's achievable rate is analyzed, and an algorithm to approximate the FAS configuration at each user is proposed based on the rate. Extensive link-level simulation results reveal that OFDM-FAMA can significantly improve the multiplexing gain over the OFDM system with fixed-position antenna (FPA) users, especially when robust channel coding is applied and the number of radio-frequency (RF) chains at each user is small.

Problem

• 5G Network
• OFDM-FAMA
• Multi-Path Environment

Innovation

• OFDM-FAMA
• 5G network
• multipath environment