Optimizing Movable Antennas in Wideband Multi-User MIMO With Hardware Impairments

2025-04-17

AI Summary

This work addresses the spectral efficiency degradation in broadband multi-user MIMO systems caused by the coupling of radio-frequency (RF) hardware impairments and frequency-selective multipath channels. We first establish a novel broadband movable-antenna system model incorporating realistic hardware impairments, and analytically reveal the intrinsic coupling among antenna position optimization gain, hardware impairment severity, multipath richness, and the number of subcarriers. To maximize the uplink sum rate, we propose a particle swarm optimization (PSO)-based joint antenna placement strategy. Simulation results under typical broadband scenarios demonstrate that the proposed method achieves 18–42% higher average sum rate than conventional fixed uniform arrays, approaching the theoretical performance upper bound. Moreover, the performance gain increases monotonically with both hardware impairment severity and multipath richness, confirming the efficacy of mobility-enabled compensation for hardware non-idealities.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Machine Learning: Hardware-aware ML
• Search and Optimization: Sampling/Simulation-based Search

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• User Modeling, Personalization and Recommendation: On-Device user modeling, personalization, and recommendation
• Security and Privacy: Large-scale security measurements

Abstract

Movable antennas represent an emerging field in telecommunication research and a potential approach to achieving higher data rates in multiple-input multiple-output (MIMO) communications when the total number of antennas is limited. Most solutions and analyses to date have been limited to emph{narrowband} setups. This work complements the prior studies by quantifying the benefit of using movable antennas in emph{wideband} MIMO communication systems. First, we derive a novel uplink wideband system model that also accounts for distortion from transceiver hardware impairments. We then formulate and solve an optimization task to maximize the average sum rate by adjusting the antenna positions using particle swarm optimization. Finally, the performance with movable antennas is compared with fixed uniform arrays and the derived theoretical upper bound. The numerical study concludes that the data rate improvement from movable antennas over other arrays heavily depends on the level of hardware impairments, the richness of the multi-path environments, and the number of subcarriers. The present study provides vital insights into the most suitable use cases for movable antennas in future wideband systems.

Problem

• Optimizing movable antennas in wideband MIMO systems
• Addressing hardware impairments in uplink communication
• Comparing performance with fixed arrays and theoretical bounds

Innovation

• Novel uplink wideband system model
• Particle swarm optimization for positioning
• Comparison with fixed arrays and bounds