OFDM Enabled Over-the-Air Computation Systems with Two-Dimensional Fluid Antennas

2026-02-08

AI Summary

This work addresses the performance limitations of over-the-air computation (AirComp) in frequency-selective channels by investigating an OFDM-based AirComp system that incorporates, for the first time, a two-dimensional fluid antenna architecture. The study formulates a joint optimization of transmit precoding, antenna positions, and receive combining to minimize the computation mean-square error (MSE). To tackle this non-convex problem, an efficient algorithm is developed based on the majorization-minimization (MM) framework combined with sequential optimization techniques. Simulation results demonstrate that the proposed scheme significantly outperforms benchmark systems with fixed antenna positions, achieving a substantial reduction in computation MSE under identical conditions, thereby validating the potential and effectiveness of fluid antennas in enhancing AirComp performance.

Technology Category

• Search and Optimization: Mixed Discrete/Continuous Search
• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Machine Learning: Optimization

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Data management and stream processing for Web, mobile and wireless applications
• Economics, Online Markets and Human Computation: Incentives in network design for Web infrastructures and ecosystems
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs

Abstract

Fluid antenna system (FAS) is able to exploit spatial degrees of freedom (DoFs) in wireless channels. In this letter, to exploit spatial DoFs in frequency-selective environments, we investigate an orthogonal frequency division multiplexing enabled over-the-air computation system, where the access point is equipped with a two-dimensional FAS to enhance performance. We solve the computation mean square error (MSE) minimization problem by transforming the original problem into transmit precoders optimization problem and antenna positions optimization along with receive combiners optimization problem. The latter is solved via a majorization-minimization approach combined with sequential optimization. Numerical results confirm that the proposed scheme achieves MSE reduction over the scheme with fixed position antennas.

Problem

• over-the-air computation
• fluid antenna system
• OFDM
• spatial degrees of freedom
• computation MSE

Innovation

• Fluid Antenna System
• Over-the-Air Computation
• OFDM
• Spatial Degrees of Freedom
• MSE Minimization