Power-splitting Energy Harvesting Research Articles

Maximizing Reliability in Overlay Radio Networks With Time Switching and Power Splitting Energy Harvesting

Maximizing Reliability in Overlay Radio Networks With Time Switching and Power Splitting Energy Harvesting

Uplink and downlink of energy harvesting NOMA system: performance analysis

ABSTRACT In this paper, we consider an uplink non-orthogonal multiple access (NOMA) for energy harvesting at the base station or access point in the wireless system. By exploiting energy enough, a base station or access point can serve many users at the downlink. The fixed power allocation factors are adopted, and the power splitting energy harvesting protocol brings many benefits to both the uplink and downlink of a wireless system. The closed-form expressions of outage probability are investigated and examined in a group of two users. Moreover, the optimal outage probability for two users is shown numerically. Finally, Monte Carlo simulations are presented to further support the validity of our framework and findings.

Worst-Case Energy Efficiency in Secure SWIPT Networks With Rate-Splitting ID and Power-Splitting EH Receivers

This paper studies the robust beamforming design for simultaneous wireless information and power transfer (SWIPT)-enabled networks, where the rate-splitting (RS) scheme and the power-splitting (PS) energy harvesting (EH) receiver are adopted for secure information transfer and EH, respectively. In order to explore the worst-case energy efficiency (EE) performance limit of the system, an EE maximization problem is formulated with the elliptically bounded channel state information error model under the constraints of the quality of service (QoS) requirements of information decoding users, the EH requirements of EH users and the power budget at the transmitter. To tackle the formulated non-convex problem, a sequential minimal optimization-based algorithm is first proposed to construct a mapping table and the optimal PS ratios of the PS EH receiver are found by searching the table. Then, a dual-layer iterative algorithm is designed to obtain the maximal EE based on the Dinkelbach’s method in the inner loop and the successive convex approximation method in the outer loop. To accelerate the convergence of the outer loop, an efficient initialization algorithm is also designed. Simulation results show that the RS scheme contributes to the EE enhancement, and the PS EH receiver enlarges the rate-energy region restricted by the non-linear EH circuit. Moreover, traditional sum-rate maximization design and power minimization design may induce a notable worst-case EE performance loss at the high-power region and the low-QoS requirement region, respectively.

User selection protocols in FD PSP EH cooperative network over rayleigh fading channel: outage and intercept probability

In this paper, we investigate the system performance in term of outage probability (OP) and intercept probability (IP) user selection protocols in full-duplex (FD) power splitting protocol (PSP) energy harvesting (EH) cooperative network over the Rayleigh fading channel. In this network, security and privacy issues are significant due to the possible eavesdropping by surrounding users. In this case, the security performance and reliable performance are represented by outage probability (OP) and intercept probability (IP), respectively. The power-splitting energy harvesting protocol is applied in our analysis. We rigorously derive the closed-form expressions of both OP and IP of the system and study the effect of various parameters. Finally, the Monte Carlo simulation results are also performed to confirm the correctness of all theoretical analysis derived.

Performance analysis for power-splitting energy harvesting based two-way full-duplex relaying network over nakagami-m fading channel

Energy harvesting relay network is considered as the promising solution for a wireless communication network in our time. In this research, we present and demonstrate the system performance of the energy harvesting based two-way full-duplex relaying network over Nakagami-m fading environment. Firstly, we propose the analytical expressions of the achievable throughput and outage probability of the proposed system. In the second step, the effect of various system parameters on the system performance is presented and investigated. In the final step, the analytical results are also demonstrated by Monte-Carlo simulation. The numerical results demonstrated and convinced the analytical and the simulation results are agreed with each other.

Cooperative non‐orthogonal multiple access with SWIPT over Nakagami‐m fading channels

AbstractTo meet with both the energy and spectral efficiency, cooperative non‐orthogonal multiple access (NOMA) (termed as CNOMA) and simultaneous wireless information and power transfer (SWIPT) are integrated in this paper. Two different protocols such as CNOMA‐SWIPT‐PS and CNOMA‐SWIPT‐TS are proposed, by employing power‐splitting (PS) and time‐switching (TS) energy harvesting (EH) techniques, respectively. In the proposed protocols, a base station (BS) directly communicates with a NOMA near user, whereas the communication with a NOMA far user is performed with the assistance of an energy‐constrained relay node. The relay node harvests energy from the transmitted signal by the BS, employing PS or TS EH technique. We investigate ergodic sum capacity and outage probability of the proposed protocols along with analytical derivations over Nakagami‐m fading channels. Finally, the effectiveness of the proposed schemes over existing strategy and conventional multiple access is demonstrated through analysis and simulation.

Global Energy Efficiency in Secure MISO SWIPT Systems With Non-Linear Power-Splitting EH Model

This paper considers an MISO simultaneous wireless information and power transfer (SWIPT) system, where one transmitter serves multiple authorized receivers in the presence of several potential eavesdroppers (idle receivers). To prevent the information interception by eavesdroppers, artificial noise (AN) is embedded into the transmit signals. The non-linear energy harvesting (EH) model is adopted and a novel power-splitting (PS) EH receiver architecture is proposed. Stochastic uncertainty channel model (SUM) is considered for the idle receivers due to outdated channel feedback. A global energy efficiency (GEE) maximization problem is formulated by jointly optimizing the transmit beamforming vectors, the AN covariance matrix, and the PS ratios, under the minimal rate and secure transmission constraints of authorized receivers, the EH requirement constraints of idle receivers, and the total available power constraint at the transmitter. Since the problem is non-convex with no known solution, it is solved based on the following solution framework. Firstly, the PS ratios are optimized by using the bisection method and successive convex approximation (SCA), and then, the transmit beamforming vectors and the AN covariance matrix are jointly optimized by using a Dinkelbach’s Algorithm based method, where SCA is applied to solve its inner subproblem. It is theoretically proved that by involving AN, the system GEE can be improved. Numerous results show that system GEE first increases and then keeps unchanged with the increment of the total available power, but it first keeps unchanged and then decreases with the increment of the minimal rate requirement. It is also observed that compared with traditional EH receiver architecture and linear EH model, our proposed PS EH receiver architecture is able to achieve higher GEE and avoid false output power at idle receivers.

Cooperative SWIPT Transmission in Overlay Multi-Antennas Hierarchical Cognitive Radio Networks

In this paper, we propose a new multi-antennas hierarchical cognitive radio, in which a primary system (PS) not only shares the spectrum resources with a secondary system (SS), but also harvests energy from the SS, achieving a new simultaneous wireless information and power transfer paradigm. Specifically, the secondary transmitter (ST) can help relay PS’s signals via an amplify-and-forward protocol, and a power splitting energy harvesting device is additionally adopted at the primary receiver (PR). A cooperative strategy is proposed for maximizing the achievable rate of the SS while ensuring PS’s achievable rate and PR’s harvested energy, by jointly optimizing a precoder at the primary transmitter, two precoders at the ST (for the PS and SS, respectively), an equalizer at the secondary receiver, and a power splitting factor for the PR. Since the optimization problem is complicated and non-convex, we propose an alternating optimization approach to decompose the original problem into three subproblems, which can finally be formulated as semi-definite programming, difference of convex, and generalized eigenvalue problems. The closed-form solutions are, then, tractably derived. The numerical results are carried out to demonstrate the effectiveness of the proposed design.

Cooperative Energy Harvesting Cognitive Radio Networks With Spectrum Sharing and Security Constraints

Physical layer security is an important and timely topic in the research of future wireless systems and it constitutes a part of the Internet of Things (IoT) notion. IoT oriented systems are largely characterized by a stringent quality of service and enhanced security requirements, which comes at a cost of increased computational complexity that needs to be maintained within sustainable levels. In the present contribution, we investigate the physical-layer security of a dual-hop energy RF-Powered cognitive radio network over realistic multipath fading conditions. Assuming a spectrum sharing scenario, our analysis assumes that a source S communicates with a destination D with the aid of a multi-antenna relay R and in the presence of an eavesdropper E who is attempting to overhear the communication of both S-R and R-D links. The involved relay is powered by the renewable energy harvested from the signal sent by the source based on the power-splitting energy harvesting strategy. Furthermore, the relay uses a maximum ratio combining technique to process effectively the received signals. In addition, owing to the underlying strategy, both S and R adjust their respective transmit powers in order to avoid causing interference to the primary network. By considering both the independent identically distributed and the independent but not necessarily identically distributed flat Rayleigh fading channels, closed-form expressions for the secrecy outage probability are derived, based on which an asymptotic analysis is carried out. Our results quantify the impact of the main key system parameters and point out the optimal values ensuring a high-security performance of such a communication system. The validity of the derived results is verified extensively through comparisons with respective Monte Carlo simulation results and useful theoretical and technical insights are developed which are expected to be useful in the design of future cooperative CRNs.

Multi-Hop Relaying Using Energy Harvesting

In this letter, the performance of multi-hop relaying using energy harvesting is evaluated. Both amplify-and-forward and decode-and-forward relaying protocols are considered. The evaluation is conducted for time-switching energy harvesting as well as power-splitting energy harvesting. The largest number of hops given an initial amount of energy from the source node is calculated. Numerical results show that, in order to extend the network coverage using multi-hop relaying, time-switching is a better option than power splitting and in some cases, decode-and-forward also supports more hops than amplify-and-forward.