Recent Advances in Joint Wireless Energy and Information Transfer

In this paper, we provide an overview of the recent advances in microwave-enabled wireless energy transfer (WET) technologies and their applications in wireless communications. Specifically, we divide our discussions into three parts. First, we introduce the state-of-the-art WET technologies and the signal processing techniques to maximize the energy transfer efficiency. Then, we discuss an interesting paradigm named simultaneous wireless information and power transfer (SWIPT), where energy and information are jointly transmitted using the same radio waveform. At last, we review the recent progress in wireless powered communication networks (WPCN), where wireless devices communicate using the power harvested by means of WET. Extensions and future directions are also discussed in each of these areas.Comment: Conference submission accepted by ITW 201

Wireless information and power transfer: from scientific hypothesis to engineering practice

Recently, there has been substantial research interest in the subject of Simultaneous Wireless Information andPower Transfer (SWIPT) owing to its cross-disciplinary appeal and its wide-ranging application potential, whichmotivates this overview. More explicitly, we provide a brief survey of the state-of-the-art and introduce severalpractical transceiver architectures that may facilitate its implementation. Moreover, the most important link-levelas well as system-level design aspects are elaborated on, along with a variety of potential solutions and researchideas. We envision that the dual interpretation of Radio Frequency (RF) signals creates new opportunities as wellas challenges requiring substantial research, innovation and engineering efforts

Multi-user Scheduling Schemes for Simultaneous Wireless Information and Power Transfer

In this paper, we study the downlink multi-user scheduling problem for a time-slotted system with simultaneous wireless information and power transfer. In particular, in each time slot, a single user is scheduled to receive information, while the remaining users opportunistically harvest the ambient radio frequency (RF) energy. We devise novel scheduling schemes in which the tradeoff between the users' ergodic capacities and their average amount of harvested energy can be controlled. To this end, we modify two fair scheduling schemes used in information-only transfer systems. First, proportionally fair maximum normalized signal-to-noise ratio (N-SNR) scheduling is modified by scheduling the user having the jth ascendingly ordered (rather than the maximum) N-SNR. We refer to this scheme as order-based N-SNR scheduling. Second, conventional equal-throughput (ET) fair scheduling is modified by scheduling the user having the minimum moving average throughput among the set of users whose N-SNR orders fall into a certain set of allowed orders Sa (rather than the set of all users). We refer to this scheme as order-based ET scheduling. The feasibility conditions required for the users to achieve ET with this scheme are also derived. We show that the smaller the selection order j for the order-based N-SNR scheme, and the lower the orders in Sa for the order-based ET scheme, the higher the average amount of energy harvested by the users at the expense of a reduction in their ergodic capacities. We analyze the performance of the considered scheduling schemes for independent and non-identically distributed (i.n.d.) Ricean fading channels, and provide closed-form results for the special case of i.n.d. Rayleigh fading.Comment: 6 pages, 3 figures. Submitted for possible conference publicatio

Robust Secrecy Beamforming for MIMO SWIPT with Probabilistic Constraints

This paper considers simultaneous wireless information apower transfer (SWIPT) in a multiple-input multiple-output (MIMO) wiretapnd power transfer (SWIPT) in a multiple-input multiple-output (MIMO) wiretap channel with energy harvesting receivers. The main objective is to keep the probability of the legitimate user's achievable secrecy rate outage as well as the energy receivers' harvested energy outage as caused by CSI uncertainties below given thresholds. This probabilistic-constrained secrecy rate maximization problem presents a significant analytical and computational challenge since any closed-form for the probabilistic constraints with log-det functions is intractable. In this paper, we address this challenging issue using codeviation inequalitiesnvex restrictions. In particular, we derive decomposition-based large deviation inequalities to transform the probabilistic constraints into second-order cone (SOC) constraints which are easier to handle. Then we show that a robust safe solution can be obtained through solving two convex sub-problems in an alternating fashion

Secure Energy-Efficient Multi-RIS-aided SWIPT Networks

© 2023, IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. This is the accepted manuscript version of a conference paper which has been published in final form at https://doi.org/10.1109/VCC60689.2023.10474823This paper considers a SWIPT network in which an access point (AP) serves multiple information decoding receivers(IDRs) and energy harvesting receivers (EHRs) assisted by several dynamically controlled reconfigurable intelligent surfaces (RIS).An energy efficiency (EE) maximization problem is formulated by the joint optimization of the transmit beamforming, artificial noise (AN) covariance, the passive beamforming at the RISs, and the RIS on/off control mechanism. Due to the non-convexity of theproblem, semi-definite relaxation (SDR) is utilized to simplify the problem. A practical solution based on alternation optimization is proposed to obtain the suboptimal solution. Furthermore, a low complexity greedy search method is proposed for the RIS on/off control. Simulation results show that the EE is significantly enhanced by employing dynamic control of multiple RIS with AN. In addition, the effect of increasing the circuit power and the number of RISs can be harmful to the system-wide EE