scholarly journals Energy Harvesting and Information Transmission Mode Design for Cooperative EH-Abled IoT Applications in beyond 5G Networks

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Hongyuan Gao ◽  
Shibo Zhang ◽  
Yumeng Su ◽  
Ming Diao

Energy harvesting (EH) technology is considered to be a promising approach to provide enough energy for energy-constrained Internet of Things (IoT). In this paper, we propose an energy harvesting and information transmission mode for the spectrum sharing system with cooperative EH-abled IoT applications in beyond 5G networks. Different from most existing IoT spectrum-sharing research studies, in our system, both primary user (PU) and IoT devices (IDs) collect energy for their information transmission. In addition, for all IDs, they should realize two communication functions: working as relays to help the information transfer process of PU and completing their own information transmission. We analytically derive exact expressions for the throughput of the primary system and IoT system and then formulate two objective functions. It is easy to see that power splitting ratio, dynamic EH ratio, power sharing ratio, and relay selection should be optimized to get the best performance for different communication circumstances. Actually, it is a hybrid NP-hard problem to optimize these parameters and traditional algorithms cannot solve it well. Therefore, a novel algorithm-quantum whale optimization algorithm (QWOA) is proposed to obtain the best performance. Simulation results show the good performance of QWOA in different simulation scenarios.

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Kang Liu ◽  
Qi Zhu ◽  
Ying Wang

Energy harvesting (EH) combined with cooperative relying plays a promising role in future wireless communication systems. We consider a wireless multiple EH relay system. All relays are assumed to be EH nodes with simultaneous wireless and information transfer (SWIPT) capabilities, which means the relays are wirelessly powered by harvesting energy from the received signal. Each EH node separates the input RF signal into two parts which are, respectively, for EH and information transmission using the power splitting (PS) protocol. In this paper, a closed-form outage probability expression is derived for the cooperative relaying system based on the characteristic function of the system’s probability density function (PDF) with only one relay. With the approximation of the outage probability expression, three optimization problems are built to minimize the outage probability under different constraints. We use the Lagrange method and Karush–Kuhn–Tucker (KKT) condition to solve the optimization problems to jointly optimize the relay’s PS factors and the transmit power. Numerical results show that our derived expression of the outage probability is accuracy and gives insights into the effect of various system parameters on the performance of protocols. Meanwhile, compared with the no optimal condition, our proposed optimization algorithms can all offer superior performance under different system constraints.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Yuanyuan Yao ◽  
Changchuan Yin ◽  
Sai Huang

The simultaneous wireless information and power transfer (SWIPT) in a cooperative relaying system is investigated, where the relay node is self-sustained by harvesting radiofrequency (RF) energy from the source node. In this paper, we propose a time switching and power splitting (TSPS) protocol for the cooperative system with a mobile destination node. In the first part of the transmission slot, a portion of the received signal power is used for energy transfer, and the remaining power is used for information transmission from the source to the relay. For the remaining time of the transmission slot, information is transmitted from the relay to a mobile destination node. To coordinate the wireless information and power transfer, two transmission modes are investigated, namely, relay-assisted transmission mode and nonrelay mode, respectively. Under these two modes, the outage probability and the network throughput are characterized. By joint optimization of the power splitting and the time switching ratios, we further compare the network throughput under the two transmission modes with different parameters. Results indicate that the relay-assisted transmission mode significantly improves the throughput of the wireless network.


IEEE Access ◽  
2016 ◽  
Vol 4 ◽  
pp. 3647-3658 ◽  
Author(s):  
Hongyuan Gao ◽  
Waleed Ejaz ◽  
Minho Jo

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Khuong Ho-Van ◽  
Thiem Do-Dac

This paper selects an unlicensed relay among available self-powered relays to not only remain but also secure information transmission from an unlicensed source to an unlicensed destination. The relays harvest energy in signals of the unlicensed source and the licensed transmitter. Then, they spend the harvested energy for their relaying operation. Conditioned on the licensed outage restriction, the peak transmission power restriction, Rayleigh fading, and the licensed interference, the current paper proposes an exact closed-form formula of the secrecy outage probability to quickly evaluate the secrecy performance of the proposed relay selection method in cognitive radio networks with energy harvesting. The proposed formula is corroborated by computer simulations. Several results illustrate the effectiveness of the relay selection in securing information transmission. Additionally, the security capability is saturated at large peak transmission powers or large preset outage probabilities of licensed users. Furthermore, the security capability depends on many specifications among which the power splitting ratio, the relays’ positions, and the time switching ratio can be optimally selected to obtain the best security performance.


Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3254 ◽  
Author(s):  
Ashish Rauniyar ◽  
Paal Engelstad ◽  
Olav Østerbø

Amidst the rapid development of the fifth generation (5G) networks, Internet of Things (IoT) is considered as one of the most important part of 5G next generation networks as it can support massive object communications. These massive object communications in the context of IoT is expected to consume a huge power. Furthermore, IoT sensors or devices are rather power constrained and are mostly battery operated. Therefore, energy efficiency of such network of IoT devices is a major concern. On the other hand, energy harvesting (EH) is an emerging paradigm that allows the wireless nodes to recharge themselves through radio frequency (RF) signals directed to them from the source node and then relaying or transmitting the information. Although a myriad of works have been carried out in the literature for EH, the vast majority of those works only consider RF EH at the relay node and successfully transmitting the source node data. Those approaches do not consider the data transmission of the relay node that may be an energy deprived IoT node which needs to transmit its own data along with the source node data to their respective destination nodes. Therefore, in this paper, we envisioned a RF EH and information transmission system based on time switching (TS) relaying, power splitting (PS) relaying and non-orthogonal multiple access (NOMA) which is suitable for wireless powered IoT relay systems. A source node information data is relayed through power constrained IoT relay node I o T R that first harvests the energy from source node RF signal using either TS and PS relaying protocol and then transmits the source node information along with its information using NOMA protocol to the respective destination nodes. Considering NOMA as a transmission protocol, we have mathematically derived analytical expressions for TS and PS relaying protocol for our proposed system. We have also formulated an algorithm to find out optimal TS and PS factor that maximizes the sum-throughput for our proposed system. Our proposed system analytical results for TS and PS protocol are validated by the simulation results.


Author(s):  
Baofeng Ji ◽  
Zhenzhen Chen ◽  
Yuqi Li ◽  
Sudan Chen ◽  
Guoqiang Zheng ◽  
...  

AbstractThis paper proposed a system architecture model of two-hop unmanned aerial vehicle (UAV) relay wireless communication and designed an energy harvesting and information transmission algorithm based on the energy harvested by UAV relay node. The energy of nodes except source node can be obtained by energy harvesting and all the UAV relay nodes transmitted signals via power splitting. Under the advance of non-static channel, the information user nodes were configured with multiple antennas and adopted max ratio combination (MRC). Based on the optimization criterion of energy efficiency maximization, the analytical solution of the optimal power allocation scheme for energy harvested and information transmission of multi-user two-UAV relay system was derived in detail. Since the optimization problem was a non-convex problem, this paper adopted the high signal-to-noise ratio approximation method and the power splitting method to realize the closed-form solution expression. The optimal solution of the objective function subjected with constraints can be obtained by Lagrangian algorithm and Lambert W function. Finally, the proposed algorithms and theoretical analysis are verified by simulations.


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