On the Performance of Unmanned Aerial Vehicles with MIMO VLC

TL;DR

This paper investigates a MIMO VLC system using UAVs with LED arrays, proposing a hybrid dimming control and a reinforcement learning-based resource allocation to enhance energy efficiency and data rate under mobility and partial CSI conditions.

Contribution

It introduces a novel hybrid dimming scheme and a SAC-based optimization framework with meta-learning for UAV-based MIMO VLC systems, addressing energy and mobility challenges.

Findings

Upgrading to a 10-LED array improves data rate by 47%.

Energy efficiency increases by 34%.

Power consumption rises by 8%..

Abstract

This paper centers around a multiple-input-multiple-output (MIMO) visible light communication (VLC) system, where an unmanned aerial vehicle (UAV) benefits from a light emitting diode (LED) array to serve photo-diode (PD)-equipped users for illumination and communication simultaneously. Concerning the battery limitation of the UAV and considerable energy consumption of the LED array, a hybrid dimming control scheme is devised at the UAV that effectively controls the number of glared LEDs and thereby mitigates the overall energy consumption. To assess the performance of this system, a radio resource allocation problem is accordingly formulated for jointly optimizing the motion trajectory, transmit beamforming and LED selection at the UAV, assuming that channel state information (CSI) is partially available. By reformulating the optimization problem in Markov decision process (MDP) form, we propose a soft actor-critic (SAC) mechanism that captures the dynamics of the problem and optimizes its parameters. Additionally, regarding the high mobility of the UAV and thus remarkable rearrangement of the system, we enhance the trained SAC model by integrating a meta-learning strategy that enables more adaptation to system variations. By defining energy efficiency as a trade-off between the data rate and power consumption, simulations verify that upgrading a single-LED UAV by an array of 10 LEDs, exhibits 47% and 34% improvements in data rate and energy efficiency, albeit at the expense of 8% more power consumption.