scholarly journals Optimal Time Assignment Policy for Maximizing Throughput in Cognitive Sensor Network with Energy Harvesting

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2540 ◽  
Author(s):  
Hao Wu ◽  
Yong Chen

A cognitive sensor network with energy harvesting (EH-CSN) is a promising paradigm to address the issues both in spectrum efficiency and in energy efficiency. The cognitive sensors (CSs) equipped with energy harvesting devices are assumed to operate in a harvesting-sensing-transmission mode and permitted to access the idle licensed frequency bands without causing any harmful jamming to the primary user. By identifying the time fractions of harvesting, sensing, and transmission, we can discuss some design considerations for the EH-CSN. In the meantime, considering the possibility that the primary user may reoccupy the idle channel during the CS’s data transmission duration, we formulate an optimization problem to maximize the average throughput of EH-CSN under a collision constraint and an energy constraint. After deriving the lower and upper bounds of the time fraction for energy harvesting, the uniqueness and existence of the optimal time fraction set have been proved. Finally, our theoretical analysis is also verified through numerical simulations.

2020 ◽  
Vol 13 (2) ◽  
pp. 173-182
Author(s):  
M. Balasubramanian ◽  
V. Rajamani

Background: The importance of this paper is to achieve maximum spectrum efficiency and proper channel allotment between Primary and Secondary User. The licensed and unlicensed users gets promoted as the channel allotment is properly carried out. To improve energy capability and spectral proficiency consider energy collecting cognitive radio systems to update both energy feasibility and spectral viability. Energy Harvesting Provides possibility of sharing energy in wireless networks which improves the performance of channel capacity. Methods: In this paper an Token Passing algorithm is proposed that switches the channels between Primary User and Secondary User. The energy efficiency decision is taken according to when primary user is idle or not. When the primary user is idle the secondary user cannot harvest any energy and when the primary channel is occupied the secondary channel harvest energy from primary user so that the harvested energy will be used by the secondary user during channel allotment. This proposed algorithm provides energy harvesting and spectrum efficiency. Results: The result shows that the most extraordinary achievable throughput R (eh) of the energy harvesting cognitive radio. The State Transition will move from busy to idle and idle to busy which is represented as S0 and S1. The other parameters are Sensing Energy es, Sampling frequency fs, Primary Signal which accepts a noise SNR γp. As Token Passing Algorithm provides tokens for primary and secondary user it takes lesser time and achieves better throughput than the FDMA and suboptimal algorithm. Conclusion: This paper achieves the maximum spectrum efficiency and energy harvesting by properly allotting spectrum for both primary and secondary user. The primary user and secondary user and spectrum management perform the channel allotment efficiently through the idle and busy state and Token Passing Algorithm does energy harvesting. An efficient scheme is developed for allocating energy in energy harvesting cognitive radio systems.


2010 ◽  
Vol 2 (2) ◽  
pp. 80-92
Author(s):  
Rupesh Patel ◽  
Atanas A. Popov ◽  
Stewart McWilliam

RSC Advances ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 3363-3370
Author(s):  
Ang Yang ◽  
Yu Qiu ◽  
Dechao Yang ◽  
Kehong Lin ◽  
Shiying Guo

In this paper, experimental and theoretical studies of the piezoelectric effect of two-dimensional ZnO nanostructures, including straight nanosheets (SNSs) and curved nanosheets (CNSs) are conducted.


Fuels ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 168-178
Author(s):  
Marzia Quaglio ◽  
Daniyal Ahmed ◽  
Giulia Massaglia ◽  
Adriano Sacco ◽  
Valentina Margaria ◽  
...  

Sediment microbial fuel cells (SMFCs) are energy harvesting devices where the anode is buried inside marine sediment, while the cathode stays in an aerobic environment on the surface of the water. To apply this SCMFC as a power source, it is crucial to have an efficient power management system, leading to development of an effective energy harvesting technique suitable for such biological devices. In this work, we demonstrate an effective method to improve power extraction with SMFCs based on anodes alternation. We have altered the setup of a traditional SMFC to include two anodes working with the same cathode. This setup is compared with a traditional setup (control) and a setup that undergoes intermittent energy harvesting, establishing the improvement of energy collection using the anodes alternation technique. Control SMFC produced an average power density of 6.3 mW/m2 and SMFC operating intermittently produced 8.1 mW/m2. On the other hand, SMFC operating using the anodes alternation technique produced an average power density of 23.5 mW/m2. These results indicate the utility of the proposed anodes alternation method over both the control and intermittent energy harvesting techniques. The Anode Alternation can also be viewed as an advancement of the intermittent energy harvesting method.


2016 ◽  
Vol 3 (2) ◽  
Author(s):  
R. V. Petrov ◽  
N. A. Kolesnikov ◽  
M. I. Bichurin

AbstractThe article is devoted to researching the practical application of the magnetoelectric effect for the development of energy harvesting devices, in particular for the design of magnetoelectric synchronous generator. The energy harvesting devices are designed to provide by the energy of remote or nonvolatile electronic devices that don’t require the high power consumption. General dimensions of the generator were as follows: diameter of 12 cm, thickness of 2.4 cm. The model of generator comprising eight ME elements with dimensions of one element of 40×10×0.5 mm at the frequency of the alternating magnetic field of 38 Hz provides the output constant voltage of 1.12 V and current of 3.82 microamps. Variable voltage before the rectifier was of 1.7 V. Total generated power was of 4.28 µW. The studies of resonant and non-resonant mode of ME element were carried out. Resonance mode of ME element provides a much greater output power. Designed generator can be applied in the construction of wind power sets, hydrogenerators, turbogenerators and other power generation equipment.


Small ◽  
2016 ◽  
Vol 12 (19) ◽  
pp. 2536-2548 ◽  
Author(s):  
Siu-Fung Leung ◽  
Qianpeng Zhang ◽  
Mohammad Mahdi Tavakoli ◽  
Jin He ◽  
Xiaoliang Mo ◽  
...  

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