More Robust Decode-and-Forward Relaying over Impulsive Noise Power Line Channels

—This paper discusses the issue of energy-efficiency in power line communication (PLC) systems and introduces decode-and-forward (DF) energy-harvesting based relaying. The performance of the proposed system is analyzed in terms of the energy efficiency for which accurate analytical expressions are derived. To highlight the achievable gains, we also evaluate the performance of both the conventional DF relaying and the directlink systems. The presented simulated results clearly demonstrate the correctness of our analysis as well as the advantage of the proposed system over the conventional relaying and direct-link approaches. Additionally, it is shown that the proposed scheme will become more energy efficient as the harvested noise energy becomes larger

On the Performance Analysis of WPT-based Dual-Hop AF Relaying Networks in α-μ Fading

In this paper, a two-hop amplify-and-forward relaying system, where an energy-constrained relay node entirely depends on the energy scavenged from the source signal, is investigated. This paper analyzes the performance of the energy-harvesting (EH) protocols, namely, ideal relaying receiver (IRR), power-splitting relaying (PSR) and time-switching relaying (TSR), over independent but not identically distributed (i.n.i.d.) α-μ fading channels in terms of the ergodic capacity and ergodic outage probability (OP). We derive exact unified and closed-form analytical expressions for the performance metrics with the aforementioned protocols over i.n.i.d. α-μ channels. Three fading scenarios, such as Weibull, Nakagami-m and Rayleigh channels, are investigated. Provided simulation and numerical results validate our analysis. It is demonstrated that the optimal EH time-switching and power-splitting factors of the corresponding TSR and PSR protocols are critical in achieving the best system performance. Finally, we analyzed the impact of the fading parameters α and μ on the achievable ergodic OP

For More Energy Efficient Dual-hop DF Relaying Power Line Communication Systems

Energy efficiency in multi-hop cooperative power line communication (PLC) systems has recently received considerable attention in the literature. In order to make such systems more energy-efficient, this paper proposes a relaying technique equipped with energy-harvesting capabilities. More specifically, we consider a dual-hop decode-and-forward (DF) broadband PLC relaying system in which the relay exploits the high noise inherent in PLC channels to further enhance energy efficiency; this system will be referred to as DF with energy-harvesting (DF-EH). This study deploys, particularly, the time-switching relaying protocol for energy-harvesting. An accurate analytical expression for the energy efficiency and a closed-form expression for the average outage probability of the proposed system are derived and then verified with Monte Carlo simulations. For the sake of comparison and to highlight the achievable gains, we also analyze the energy efficiency performances and the average outage probabilities of the conventional DF relaying system, i.e. without energy-harvesting, as well as that of the direct-link approach. Furthermore, various frequency selection and power allocation strategies, namely, optimal frequency selection, random frequency selection and equal power allocation, exploiting the multiple power cables, are studied. Then, the impact of several system parameters such as the energy-harvesting time factor, various idle power consumption profiles, relay location, power allocation as well as different noise scenarios are examined. The results reveal that the proposed DF-EH system is able to provide energy efficiency improvements of more than 30% compared to the conventional DF relaying scheme. It is also shown that the proposed system with optimal frequency selection performs better at low SNR whereas at high SNR the equal power allocation based system will have the best performance

Mechanism of the thermochemical transformation of wheat grain’s processing waste during heat treatment

The thermal destruction of wheat grain’s processing wastes from Almaty and South Kazakhstan regions was studieв. The structure of the products obtained depending on the temperature of the carbonization process was formed, and the basic physico chemical characteristics of the obtained carbon material based on the WGPW were studied using thermogravimetric analysis, differential scanning calorimetry, IR spectroscopy and EPR spectroscopy. The analysis of the elemental composition of the obtained samples of the sorption material showed that the carbon content in the composition of the obtained carbon material is 75.08 - 76.12%, which in turn can cause a sufficiently high degree of sorption capacity of this material, as well as its mechanical strength. The obtained carbon materials based on OIP were modified with ammonium nitrate (NH4NO3) to improve its physico-chemical characteristics, such as specific surface area, porosity and adsorption capacity by iodine. It is shown that structural transformations of the processing waste of wheat grain (bran) in the process of heat treatment irrespective of temperature (in the studied interval) proceed through the stage of formation of free radicals. The concentration of free radicals formed in this process, as well as the composition of the graphite-like component of the products obtained, are determined by the temperature indices of the process

Outage Analysis and Realization Challenges of RIS-enabled Underlay CR Networks over Nakagami-m Fading

Metamaterials, i.e., reconfigurable intelligent surfaces (RISs), have become very promising and advancing rapidly due to the ability to manipulate electromagnetic (EM) waves. This feature essentially ensures the versatile application area such as various imaging techniques, cloaking devices, wireless power transfer systems, holography, and cross-radar section reduction. The control of EM waves, within the idea of digital metamaterials, can be realized by employing binary coding with 1-, 2-, or more bits. In general, the programmable metasurface can assure the modification of reflected wave amplitude and phase in a certain frequency band. In another development, cognitive radio has become an effective approach for improving spectrum efficiency. Possessing promising features, this work investigates the concept of adopting both RIS and CR within a network for the purpose of increasing the possible benefits available. We simulate the practical realization of the digital metasurface using different coding elements. We obtain the exact and numerical solutions for the system's outage probability and validate the expressions via Monte Carlo simulations. Furthermore, the impacts of the Nakagami- m fading parameter, interference temperature constraint, and number of reflective elements on the system performance are examined and discussed. © 2022 IEEE

More robust decode-and-forward relaying over impulsive noise power line channels

This paper discusses the issue of energy-efficiency in power line communication (PLC) systems and introduces decode-and-forward (DF) energy-harvesting based relaying. The performance of the proposed system is analyzed in terms of the energy efficiency for which accurate analytical expressions are derived. To highlight the achievable gains, we also evaluate the performance of both the conventional DF relaying and the direct-link systems. The presented simulated results clearly demonstrate the correctness of our analysis as well as the advantage of the proposed system over the conventional relaying and direct-link approaches. Additionally, it is shown that the proposed scheme will become more energy efficient as the harvested noise energy becomes larger

Enhancing QoS Through Fluid Antenna Systems over Correlated Nakagami-m Fading Channels

Fluid antenna systems (FAS) enable mechanically flexible antennas that offer adaptability and flexibility for modern communication devices. In this work, we present a conceptual model for a single-antenna N-port (SANP) FAS over spatially correlated Nakagami-m fading channels and compare it with the traditional diversity schemes in terms of outage probability. The proposed FAS model switches to the best antenna port and resembles the operation of a selection combining (SC) diversity. FAS improves the quality of service (QoS) of the network through antenna port selection. The advantage of FAS is the ability to fit hundreds of antenna ports into a half-wavelength antenna size at the cost of spatial channel correlation. Simulation results demonstrate the superior outage probability performance of FAS at several tens of antenna ports compared to the traditional diversity schemes such as maximum ratio combining, equal gain combining, and SC. Moreover, the novel probability and cumulative density functions for the land mobile correlated Nakagami-m random variates are evaluated in this paper. © 2022 IEEE