Simultaneous Energy Harvesting and Information Transmission in a MIMO Full-Duplex System: A Machine Learning-Based Design

TL;DR

This paper introduces a MIMO full-duplex system that enables simultaneous wireless information and energy transfer, utilizing machine learning for antenna selection and precoding, resulting in improved spectral efficiency over traditional methods.

Contribution

It presents a novel MIMO FD scheme with a DRL-based antenna selection and precoding approach, enhancing spectral efficiency in simultaneous wireless information and power transfer.

Findings

DRL-based method achieves highest spectral efficiency.

System performance improves with more than three antennas per device.

Significant spectral efficiency gains over time switching-based SWIPT.

Abstract

We propose a multiple-input multiple-output (MIMO)-based full-duplex (FD) scheme that enables wireless devices to simultaneously transmit information and harvest energy using the same time-frequency resources. In this scheme, for a MIMO point-to-point set up, the energy transmitting device simultaneously receives information from the energy harvesting device. Furthermore, the self-interference (SI) at the energy harvesting device caused by the FD mode of operation is utilized as a desired power signal to be harvested by the device. For implementation-friendly antenna selection and MIMO precoding at both the devices, we propose two methods: (i) a sub-optimal method based on relaxation, and (ii) a hybrid deep reinforcement learning (DRL)-based method, specifically, a deep deterministic policy gradient (DDPG)-deep double Q-network (DDQN) method. Finally, we study the performance of the proposed system under the two implementation methods and compare it with that of the conventional time switching-based simultaneous wireless information and power transfer (SWIPT) method. Findings show that the proposed system gives a significant improvement in spectral efficiency compared to the time switching-based SWIPT. In particular, the DRL-based method provides the highest spectral efficiency. Furthermore, numerical results show that, for the considered system set up, the number of antennas in each device should exceed three to mitigate self-interference to an acceptable level.