Over-the-Air Computation via 2D Movable Antenna Array

TL;DR

This paper introduces a 2D movable antenna array for over-the-air computation, optimizing antenna positions and signal processing to reduce error and outperform fixed antennas.

Contribution

It proposes a novel 2D movable antenna array system for AirComp, with a joint optimization algorithm for antenna placement and signal processing.

Findings

Outperforms fixed-position antenna systems in simulations

Effective joint optimization of antenna positions and transmit/receive parameters

Demonstrates significant reduction in computation mean square error

Abstract

Movable antenna (MA) has emerged as a promising technology for improving the performance of wireless communication systems, which enables local movement of the antennas to create more favorable channel conditions. In this letter, we advance its application for over-the-air computation (AirComp) network, where an access point is equipped with a two-dimensional (2D) MA array to aggregate wireless data from massive users. We aim to minimize the computation mean square error (CMSE) by jointly optimizing the antenna position vector (APV), the receive combining vector at the access point and the transmit coefficients from all users. To tackle this highly non-convex problem, we propose a two-loop iterative algorithm, where the particle swarm optimization (PSO) approach is leveraged to obtain a suboptimal APV in the outer loop while the receive combining vector and transmit coefficients are alternately optimized in the inner loop. Numerical results demonstrate that the proposed MA-enhanced AirComp network outperforms the conventional network with fixed-position antennas (FPAs).