REMAA: Reconfigurable Pixel Antenna-based Electronic Movable-Antenna Arrays for Multiuser Communications

2025-04-01

AI Summary

This paper addresses the sum-rate maximization problem in multi-user communications under joint power and hardware constraints. We propose a reconfigurable electronic movable antenna array (REMAA) based on reconfigurable pixel antennas (RPAs), which achieves virtual antenna movement via discretized radiation-position selection—thereby closely approximating the performance of mechanically movable antennas while drastically reducing hardware cost. We establish, for the first time, the theoretical performance bound of REMA. Furthermore, we design a two-step joint beamforming and antenna selection (TL-JBAS) algorithm that integrates coordinate descent with alternating optimization. Crucially, we quantify, for the first time, the power loss induced by spatial discretization: only 3.25% maximum power is lost under a λ/10 position quantization step. Simulation results demonstrate that REMAA significantly outperforms conventional fixed arrays in multi-user sum rate and closely approaches the performance of continuously mechanically adjustable antennas.

Technology Category

• Search and Optimization: Mixed Discrete/Continuous Search
• Multiagent Systems: Mechanism Design
• Machine Learning: Hardware-aware ML

Application Category

• User Modeling, Personalization and Recommendation: On-Device user modeling, personalization, and recommendation
• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• Search and Retrieval-Augmented AI: Efficiency and scalability of Web search engines

Abstract

In this paper, we investigate reconfigurable pixel antenna (RPA)-based electronic movable antennas (REMAs) for multiuser communications. First, we model each REMA as an antenna characterized by a set of predefined and discrete selectable radiation positions within the radiating region. Considering the trade-off between performance and cost, we propose two types of REMA-based arrays: the partially-connected RPA-based electronic movable-antenna array (PC-REMAA) and fully-connected REMAA (FC-REMAA). Then, we formulate a multiuser sum-rate maximization problem subject to the power constraint and hardware constraints of the PC-REMAA or FC-REMAA. To solve this problem, we propose a two-step multiuser beamforming and antenna selection scheme. In the first step, we develop a two-loop joint beamforming and antenna selection (TL-JBAS) algorithm. In the second step, we apply the coordinate descent method to further enhance the solution of the TL-JBAS algorithm. In addition, we revisit mechanical movable antennas (MMAs) to establish a benchmark for evaluating the performance of REMA-enabled multiuser communications, where MMAs can continuously adjust the positions within the transmission region. We also formulate a sum-rate maximization problem for MMA-enabled multiuser communications and propose an alternating beamforming and antenna position optimization scheme to solve it. Finally, we analyze the performance gap between REMAs and MMAs. Based on Fourier analysis, we derive the maximum power loss of REMAs compared to MMAs for any given position interval. Specifically, we show that the REMA incurs a maximum power loss of only 3.25% compared to the MMA when the position interval is set to one-tenth of the wavelength. Simulation results demonstrate the effectiveness of the proposed methods.

Problem

• Design reconfigurable pixel antenna arrays for multiuser communications
• Maximize sum-rate under power and hardware constraints
• Compare performance between electronic and mechanical movable antennas

Innovation

• Reconfigurable pixel antenna-based electronic movable arrays
• Two-step multiuser beamforming and antenna selection
• Coordinate descent method for solution enhancement