Analysis and optimisation of SWIPT networks.

In cognitive Wireless Radio networks, information transfer and power transfer are given special consideration in next-generation wireless networking devices like Simultaneous Wireless Information and Power Transfer. The benefit of integrating cognitive network concepts is that it provides greater efficiency on energy and spectrum to address interference, fading, and path loss, among many other issues, in certain critical applications. Energy harvesting (EH) is a secure and cost-effective method of powering up cluster heads when needed. The proposed method considers two phases. The first phase is energy harvesting of SUs transferred in power signals send by the hybrid access point during wireless power transfer (WPT). While in the second phrase, Wireless Information Transfer (WIT) phase, the captured energy is used while simultaneously acquiring transmission possibilities. In addition, a fuzzy-based cluster using a greedy algorithm is used to reduce PU secrecy outages and to provide the best ideal result. These may be identified using a convolutional neural network (CNN) to detect and classify distinct attack types. This paper presents an efficient resource allocation using fuzzy logic-based clustering and greedy algorithms, which can provide better performance than other technologies. The subsystem for cognitive radio networks is configured, and the primary nodes’ secrecy is maintained and free of three attacks, and the results are simulated using MATLAB tools.

Far-field Wireless Power Transfer (WPT) and Simultaneous Wireless Information and Power Transfer (SWIPT) have attracted significant attention in the RF and communication communities. Despite the rapid progress, the problem of waveform design to enhance the output DC power of wireless energy harvester has received limited attention so far. In this paper, we bridge communication and RF design and derive novel multisine waveforms for multi-antenna wireless power transfer. The waveforms are adaptive to the channel state information and result from a posynomial maximization problem that originates from the non-linearity of the energy harvester. They are shown through realistic simulations to provide significant gains (in terms of harvested DC power) over state-of-the-art waveforms under a fixed transmit power constraint.

Unmanned aerial vehicles (UAVs) have recently been envisaged as an enabling technology of 5G. UAVs act as an intermediate relay node to facilitate uninterrupted, high quality communication between information sources and their destination. However, UAV energy management has been a major issue of consideration due to limited power supply, affecting flight duration. Thus, we introduce in this paper a unified energy management framework by resorting to wireless power transfer (WPT), simultaneous wireless information and power transfer (SWIPT) and self-interference (SI) energy harvesting (EH) schemes, in cooperative relay communications. In our new technique, UAVs are deployed as relays equipped with a decode and forward protocol and EH capability operating in a full-duplex (FD) mode. The UAV assists information transmission between a terrestrial base station and a user. The UAV's transmission capability is powered exclusively by the energy harvested from WPT, radio frequency signal transmitted from the source via time-switching SWIPT protocol and SI exploitation. We improve the overall system throughput by the use of FD based UAV-assisted cooperative system. In this proposed system, we formulate two optimization problems to minimize end-to-end outage probability, subject to UAV's power profile and trajectory for a DF relay scheme, respectively. The KKT conditions have been used to obtain closed-form solutions for the two formulated problems. Numerical simulation results validate all the theoretical results. We demonstrate that the performance of our proposed unified EH scheme outperforms that of existing techniques in the literature.

Far-field wireless power transfer (WPT) and simultaneous wireless information and power transfer (SWIPT) have become increasingly important in radio frequency (RF) and communication communities recently. The problem of modulation design for SWIPT has however been scarcely addressed. In this paper, a modulation scheme based on asymmetric phase-shift keying (PSK) is considered, which improves the SWIPT rate-energy tradeoff region significantly. The nonlinear rectifier model, which accurately models the energy harvester, is adopted for evaluating the output direct current (DC) power at the receiver. The harvested DC power is maximized under an average power constraint at the transmitter and a constraint on the rate of information transmitted via a multi-carrier signal over a flat fading channel. As a consequence of the rectifier nonlinearity, this work highlights that asymmetric PSK modulation provides benefits over conventional symmetric PSK modulation in SWIPT and opens the door to systematic modulation design tailored for SWIPT.

5G-based green broadband communication system design with simultaneous wireless information and power transfer

In this paper, we consider a cooperative cognitive radio relay network (CCRRN), in which there is a pair of primary transmitter (PT) and primary receiver (PR) with each having a single antenna, a secondary transmitter (ST) equipped with two antennas and a secondary receiver (SR) having a single antenna. We assume that ST operates in a half-duplex mode with an amplify-and-forward (AF) cooperative transmission scheme adopted. For such a system, a novel transmission scheme for CCRRN based on uniquely-factorable constellation pair (UFCP) is proposed, which enables ST to transmit its own information to SR without knowing its channel links to PR and SR while assisting PT transmission. It is shown that one of significant advantages of our proposed new scheme is that in a noise-free case, PR and SR are able to decode their own signals uniquely and that in a Gaussian noise case, they are still able to reliably decode their own signals with full diversity. In addition, a tight upper bound of average pairwise error probability (PEP) for the maximum likelihood (ML) detector is derived, showing that full diversity is achieved. With this, an optimal power allocation strategy is proposed that minimizes the worst-case upper bound.

Realising both wireless information transfer (WIT) and wireless power transfer (WPT) in the same RF spectral band has imposed great challenges on the system design but the spectral efficiency can be substantially improved, which triggers the significant research interest in the simultaneous wireless information and power transfer (SWIPT). In order to fully exploit the limited spectral resources, a non-orthogonal-multiple-access (NOMA) technique aided SWIPT system is considered for simultaneously realising both of WIT and WPT, which consists of a single access point (AP), a single WPT user and a pair of WIT users. The AP delivers the requested information to the pair of WIT users by adopting the NOMA technique. In order to maximise the amount of energy received by the WPT user, a novel constellation rotation based modulation scheme is proposed for constructively combining the symbols requested by the pair of the WIT users by optimising the constellation rotation angle. By considering the sensitivity of the energy harvester, the simulation results demonstrate that our modulation scheme is capable of efficiently increasing the energy harvested by the WPT user without incurring additional symbol detection errors.

In this paper, the problem of security in multiple input multiple output (MIMO) system has been analysed in the presence of an eavesdropper in cognitive radio networks. Multiple primary and secondary users communicate with the primary and secondary receiver, respectively. The secrecy capacity at primary receiver (PR) and secondary receiver (SR) have been calculated. At first, we use zero-forcing (ZF) precoding at the relay which enhances the secrecy capacity of PR and SR by nullifying the impact of interference. Secondly, we use a scheme to improve the secrecy capacity of the PR and SR using the existing interference energy of the communication medium employing selective precoding (SP) at the relay. Finally, we employ phase alignment precoding (PAP) for further increase in the secrecy capacity for PR and SR by using the destructive part of interference. Our analysis shows that among the three precoding techniques, the best performance is achieved by using the PAP at the relay in terms of secrecy capacity, complementary cumulative distribution function (CCDF) and outage probability analysis.

In this paper, we propose a destination-aided jamming scheme for secrecy simultaneous wireless information and power transfer (SWIPT) in cognitive relay networks. In which, an energy-constrained secondary transmitter (ST) assists to forward the traffic from a primary transmitter (PT) to a primary receiver (PR) and collaborates with PR-aided jamming to prevent the eavesdropper around PR from eavesdropping, in exchange for communicating with its own receiver in the same frequency. To maximize the rate of ST, we jointly design the relay processing matrix, beamforming vector and power split ratio under the constraint of PT secrecy rate demand. For tackling the non-convex problem, the semi-definite relaxation technique and Charnes-Cooper transformation are adopted. Simulation results demonstrate that our proposed scheme can significantly improve the performance of communications.

This work presents some recent solutions that exploit the wireless power transfer (WPT) technology for energizing moving vehicles and machinery tools. Such technology is currently experiencing unprecedented interests in non-traditional RF/microwave sectors fields, such the industrial automation and the railway transportation safety. Near-field electromagnetic coupling solutions are presented showing that, in order to obtain efficient performances for broad ranges of operating conditions, the nonlinear electromagnetic co-design of the entire WPT system, from the energy source to the receiver load, needs to be carried out. This technology can be combined with wireless data transfer, thus realizing integrated systems able to simultaneously control the energy transfer and the transmission of data. The adopted operating frequencies are in the MHz range, which is only recently considered for this kind of applications. In particular this work focuses on three different systems: the first one demonstrates the constant powering of “on the move” industrial charts at 6.78 MHz, regardless of the relative position of the transmitter and the receiver sub-systems; the second one presents a novel design of a balise transportation system adopting a high efficiency GaN-based transmitter designed to keep its performance over a wide range of loading conditions; the last one consists of the simultaneous wireless power and data transfer, to a rotating machinery tool, automatically controlled by the powering system based on the coexistence of frequency-diverse inductive and capacitive couplings.

This paper introduces the first reported electrically small Huygens dual-functional wireless power transfer (WPT) and communication system operating in the 915-MHz ISM band. It is realized by the seamless combination of a Huygens linearly polarized (HLP) antenna and a highly efficient HLP rectenna. The configuration consists of two orthogonally oriented HLP subsystems. Each one intrinsically combines two pairs of metamaterial-inspired near-field resonant parasitic elements, i.e., an Egyptian axe dipole (EAD) and a capacitively loaded loop (CLL). Through the development of a very tightly coupled feed subsystem that includes the WPT mode's rectifier circuit and the communications mode's feedline while preserving their isolation, the independent operation of both functions is facilitated in an electrically small volume (ka <; 0.77). The measured results of its fabricated prototype agree well with their simulated values. The communications mode antenna resonates at 910 MHz and radiates a cardioid-shaped Huygens pattern with the peak gain of 2.7 dBi. The Huygens-based WPT rectenna achieves an 87.2% peak ac-to-dc conversion efficiency at 907 MHz. The dual-functional system is an ideal candidate for many emerging Internetof-Things (IoT) wireless applications that require simultaneous wireless information and power transfer (SWIPT) and wirelessly powered communications (WPC).

This book is the first systematic exposition on the emerging domain of wireless power transfer in ad hoc communication networks. It selectively spans a coherent, large spectrum of fundamental aspects of wireless power transfer, such as mobility management in the network, combined wireless power and information transfer, energy flow among network devices, joint activities with wireless power transfer (routing, data gathering and solar energy harvesting), and safety provisioning through electromagnetic radiation control, as well as fundamental and novel circuits and technologies enabling the wide application of wireless powering. Comprising a total of 27 chapters, contributed by leading experts, the content is organized into six thematic sections: technologies, communication, mobility, energy flow, joint operations, and electromagnetic radiation awareness. It will be valuable for researchers, engineers, educators, and students, and it may also be used as a supplement to academic courses on algorithmic applications, wireless protocols, distributed computing, and networking.

Numerous efforts in wireless power transfer have concentrated on simultaneous wireless information and power transfer (SWIPT), enabling terminal devices (TDs) to achieve permanent operation and reducing the limitation of energy on information transmission. Nevertheless, most existing studies focus on the amount of energy transferred, the estimation of the harvest states of TDs, and the optimization of energy efficiency for a system, failing to investigate the timeliness of energy replenishment for TDs through wireless energy harvesting. Additionally, due to channel fading and the influence of nonlinear circuits, serious estimation errors will occur during wireless energy transmission and state of charge (SoC) evaluation, resulting in the failure of system strategies and degraded system performance. To address this issue, a novel wireless energy access quality of service (QoS) index, age of energy harvesting (AoEH), is proposed to measure the timeliness of wireless energy transfer for TDs. Based on AoEH, this paper establishes a SWIPT access channel model and revises the time sequence of access channels. Furthermore, an energy management strategy is proposed for the permanent operation of TDs, and relevant theoretical analysis on the boundlessness of remaining energy is provided. As a typical case, this paper formulates the age of information (AoI) minimization problem for SWIPT-enabled sensor networks to find the optimal energy packet generation interval at the sink node based on AoEH expressions. Corresponding solutions are proposed for the AoI minimization problem with and without maximum transmission frequency constraints. Simulation results indicate that TD’s energy is bounded and stable under the proposed energy management strategy, and the AoI optimized by the optimal energy packet generation interval algorithm is up to 30% lower compared to existing algorithms.

Resource use in point-to-point and point-to-multipoint communication emerges with the tremendous growth in wireless communication technologies. One of the technologies is wireless power transfer which may be used to provide sufficient resources for energy-constrained networks. With the implication of cooperative communication in 5G/B5G and the Internet of Things (IoT), simultaneous wireless information and power transfer (SWIPT)-assisted energy efficiency and appropriate resource use become challenging tasks. In this paper, multiple IoT-enabled devices are deployed to cooperate with the source node through intermediate/relay nodes powered by radio-frequency (RF) energy. The relay forwards the desired information generated by the source node to the IoT devices with the fusion of decode/amplify processes and charges itself at the same time through energy harvesting technology. In this regard, a problem with throughput, energy efficiency, and joint throughput with user admission maximization is formulated while assuring the useful, practical network constraints, which contemplate the upper/lower bounds of power transmitted by the source node, channel condition, and energy harvesting. The formulated problem is a mixed-integer non-linear problem (MINLP). To solve the formulated problem, the rate of individual IoT-enabled devices (b/s), number of selected IoT devices, and the sum-rate maximization are prosecuted for no-cooperation, cooperation with diversity, and cooperation without diversity. Moreover, a comparison of the outer approximation algorithm (OAA) and mesh adaptive direct search algorithm (MADS) for non-linear optimization with the exhaustive search algorithm is provided. The results with reference to the complexity of the algorithms have also been evaluated which show that 4.68×10−10 OAA and 7.81×10−11 MADS as a percent of ESA, respectively. Numerous simulations are carried out to exhibit the usefulness of the analysis to achieve the convergence to ε-optimal solution.

We develop an analytical framework to characterize the effect of impulsive noise on the performance of relay-assisted simultaneous wireless information and power transfer (SWIPT) systems. We derive novel closed-form expressions for the pairwise error probability considering two variants based on the availability of channel state information (CSI), namely, blind relaying and CSI-assisted relaying. We further consider two energy harvesting (EH) techniques, i.e., instantaneous EH (IEH) and average EH (AEH). Capitalizing on the derived analytical results, we present a detailed numerical investigation of the diversity order for the underlying scenarios under the impulsive noise assumption. For the case when two relays and the availability of a direct link, it is demonstrated that the considered SWIPT system with blind AEH-relaying is able to achieve an asymptotic diversity order of less than 3, which is equal to the diversity order achieved by CSI-assisted IEH-relaying. This result suggests that, by employing the blind AEH relaying, the power consumption of the network can be reduced, due to eliminating the need of CSI estimation. This can be achieved without any performance loss. Our results further show that placing the relays close to the source can significantly mitigate the detrimental effects of impulsive noise. Extensive Monte Carlo simulation results are presented to validate the accuracy of the proposed analytical framework.