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Omar Saraereh

The Hashemite University, Electrical Engineering Department, Faculty Member

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SITI RAHENA ISA

Universidad Nacional de Cuyo

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Papers by Omar Saraereh

A Novel Broadband Antenna Design for 5G Applications

Computers, Materials & Continua, 2021

Wireless communication is one of the rapidly-growing elds of the communication industry. This con... more Wireless communication is one of the rapidly-growing elds of the communication industry. This continuous growth motivates the antenna community to design new radiating structures to meet the needs of the market. The 5G wireless communication has received a lot of attention from both academia and industry and signi cant efforts have been made to improve different aspects, such as data rate, latency, mobility, reliability and QoS. Antenna design has received renewed attention in the last decade due to its potential applications in 5G, IoT, mmWave, and massive MIMO. This paper proposes a novel design of broadband antenna for 5G mmWave and optical communication networks. It is a hybrid structure that works for both spectrums and contains an absorption dielectric material with an electrical large size. A hybrid transmission line theory ray-tracing technique is proposed ef cient and rapid simulation and optimization of the proposed antenna design. The operating frequency and wavelength of the proposed antenna are 28 GHz in the mmWave band and 1550 nm for the optical spectrum. The spatial frequency is 30 lp/mm when the contrast transfer function is reduced to 0.7 for the optical signal. The effective focal length and aperture are 816.86 and 200 mm. The half-power beamwidth is 3.29 • and the gain is 32.97 dBi for the mmWave band. Simulation results show that the proposed hybrid antenna can effectively be deployed simultaneously for both optical and mmWave 5G communication networks.

Ultra Wideband Wearable Antenna

2019 8th Asia-Pacific Conference on Antennas and Propagation (APCAP), 2019

In this paper, a design approach of an Ultra-Wide Band microstrip patch antenna with decent perfo... more In this paper, a design approach of an Ultra-Wide Band microstrip patch antenna with decent performance and low SAR results is presented. The proposed antenna consists of conducting circular patch element etched on a dielectric printed circuit board with compact size 40×40×1.4 mm3. The design is wearable for on-body applications, flexible, light weight and suitable for 1.8 GHz DCS, 3.6/5.2 GHz WLAN and 5.8 GHz WiMAX.

An Array of M-Shaped Vivaldi Antennas for Uwb Applications

Progress In Electromagnetics Research Letters, 2017

In this paper, a novel M-shaped UWB Vivaldi array antenna is presented. First of all, a simple M-... more In this paper, a novel M-shaped UWB Vivaldi array antenna is presented. First of all, a simple M-shaped UWB Vivaldi antenna is designed, and its properties of return loss, radiation pattern, VSWR, gain, etc. are analyzed. An array of M-shaped UWB antenna is simulated and designed after the successful implementation of the simple UWB Vivaldi antenna. The designed antenna has operating frequency from 3.25 GHz to 8.85 GHz covering 5.6 GHz bandwidth. The antenna has flat gain over entire frequency range. The proposed antenna is fabricated on a commercially available FR-4 substrate having relative permittivity of 4.4 and height of 1 mm. The proposed antenna has wide band and good flat gain over entire frequency range. The proposed antenna can be used in next generation wireless communication because of its efficiency, gain and wide bandwidth.

A Hybrid Energy Harvesting Design for On-Body Internet-of-Things (IoT) Networks

Sensors, 2020

The Internet-of-things (IoT) has been gradually paving the way for the pervasive connectivity of ... more The Internet-of-things (IoT) has been gradually paving the way for the pervasive connectivity of wireless networks. Due to the ability to connect a number of devices to the Internet, many applications of IoT networks have recently been proposed. Though these applications range from industrial automation to smart homes, healthcare applications are the most critical. Providing reliable connectivity among wearables and other monitoring devices is one of the major tasks of such healthcare networks. The main source of power for such low-powered IoT devices is the batteries, which have a limited lifetime and need to be replaced or recharged periodically. In order to improve their lifecycle, one of the most promising proposals is to harvest energy from the ambient resources in the environment. For this purpose, we designed an energy harvesting protocol that harvests energy from two ambient energy sources, namely radio frequency (RF) at 2.4 GHz and thermal energy. A rectenna is used to harv...

Efficient Power Control Framework for Small-Cell Heterogeneous Networks

Sensors, 2020

Heterogeneous networks are rapidly emerging as one of the key enablers of beyond fifth-generation... more Heterogeneous networks are rapidly emerging as one of the key enablers of beyond fifth-generation (5G) wireless networks. It is gradually becoming clear to the network operators that existing cellular networks may not be able to support the traffic demands of the future. Thus, there is an upsurge in the interest of efficiently deploying small-cell networks for accommodating a growing number of user equipment (UEs). This work further extends the state-of-the-art by proposing an optimization framework for reducing the power consumption of small-cell base stations (BSs). Specifically, a novel algorithm has been proposed which dynamically switches off the redundant small-cell BSs based on the traffic demands of the network. Due to the dynamicity of the formulated problem, a new UE admission control policy has been presented when the problem becomes infeasible to solve. To validate the effectiveness of the proposed solution, the simulation results are compared with conventional technique...

Computer simulated assessment of radio frequency electromagnetic waves for the detection of obstructive sleep apnea

Informatics in Medicine Unlocked, 2019

Obstructive sleep apnea/hypopnea syndrome (OSAHS) is the most common form of sleep-disorder breat... more Obstructive sleep apnea/hypopnea syndrome (OSAHS) is the most common form of sleep-disorder breathing (SDB). Recurring restriction or occlusion of the upper airway throughout the night concurrent with continued respiratory efforts lasting more than 10 s characterizes the disorder. Prevalence of OSAHS is increasing globally, with a high association with obesity, hypertension, and heart failure. Nocturnal polysomnography (NPSG), which is the gold standard for OSAHS diagnosis, is scarce, expensive, and cumbersome. Methods for home screening and diagnosis of the disorder, directly and indirectly, are highly sought after to amend or replace NPSG. Well-established norms and procedures for electromagnetic (EM) antenna design, radiation pattern and characterization, and signal reception and measurements can be employed for the direct detection of upper airway occlusion. The utilization of radio-frequency (RF) EM antennas is desirable, as it is inexpensive, and simple to design and implement. In this paper, a computerized simulation of a new EM sensing system for direct detection of the occlusion in the upper airway is presented. Electromagnetic, anatomical, and RF safety constraints are taken into consideration. The theoretical basis of EM, antenna design, and physiological interactions with EM waves are presented. The proposed methodology for creating an anatomically-correct neck and airway simulated phantoms to test the hypothesis and the results of the tests are presented. Hypothesis: Radio-frequency electromagnetic waves transmitted through an open airway will have different energy levels at the distal side of the neck compared to those associated with a fully occluded airway. Methodology: A system is designed comprising a simulated phantom model of the upper airway and neck with the approximate anatomical dimensions and dielectric properties of homogenous neck tissue. Additionally, an RF patch antenna is designed and matched to the phantom neck. An iterative process is developed and implemented for the patch antenna design and coupling with a tissue. Simulation of the EM wave propagation and dissipation throughout the neck in the open and closed airway cases is provided and calculated based on the specific absorption ratios (SAR). The results of several permutations of antenna orientation with respect to the neck and several gaps between the antenna and the neck are provided. Results: the Computer simulations for all antenna orientation and location have shown that the EM energy levels recorded from open airway phantom models are statistically different and lower than those recorded from the occluded airway phantom models. Conclusions: The results of this study support the hypothesis that it is theoretically feasible to use electromagnetic energy to distinguish between open and occluded upper airway.

Simulated topology of doubly powered asynchronous motor with diode clamped inverter

International Journal of Power Electronics, 2019

This paper deals with the problem of modelling, control and analysis of a doubly-powered inductio... more This paper deals with the problem of modelling, control and analysis of a doubly-powered induction machine (DPIM) using a three-level three-phase voltage source inverter known simply as diode clamped inverter (DCI) with a three-phase diode rectifier and a DC link in between. A mathematical model of DPIM and the associated DCI circuit is developed. The stator circuit of the DPIM is supplied directly from an ac system network while its rotor side is supplied via a variable frequency DCI. A multi-loop nonlinear field controller is developed to meet an accurate motor speed, regulation of the mechanical load torque and the overall system power. The results obtained from the simulation in the environment of Simplorer 7 show that the proposed DCI inverter offers great optimisation, little overshoot, and reduced voltage ripples. Consequently, the dynamic behaviour of the motor and the energy efficiency of the overall system are progressively improved and a complete suppress of the influence of the variation in the motor load on the speed of the motor is achieved.

A Multiband and Omnidirectional, CPW-Fed Single-Layer Based Dual Tapered-Slot Antenna

Progress In Electromagnetics Research C, 2016

Travelling wave antennas such as Vivaldi antenna have conventionally been used for obtaining wide... more Travelling wave antennas such as Vivaldi antenna have conventionally been used for obtaining wideband and directional radiation pattern. This paper presents a novel way to obtain first of its kind, omnidirectional travelling wave antenna inspired by Vivaldi. Traditional omnidirectional antennas such as monopole and dipole rely on resonance condition which is usually satisfied on narrow band while the proposed antenna is relatively broadband owing to its travelling wave phenomenon. Moreover, typical Vivaldi antennas are double layered while our design requires only one layer. Antenna has been simulated and optimized in HFSS to operate in dual bands of UWB spectrum. The antenna has been measured and characterized using Keysight handheld VNA and Satimo Anechoic chamber. Good agreement between simulations and measurements has been obtained despite the fabrication tolerance of LPKF PCB manufacturing machine.

Design of compact and miniaturize asymmetric SIR-DRA filter-antenna subsystem

Journal of Electromagnetic Waves and Applications, 2016

The proposed work presents a compact filter-antenna subsystem design using asymmetric stepped imp... more The proposed work presents a compact filter-antenna subsystem design using asymmetric stepped impedance resonator filter and cylindrical dielectric resonator antenna. A cylindrical dielectric resonator antenna is excited from stepped impedance resonator through slot. The DRA is excited for HEM 11 mode. Rather than utilizing customary 50 Ω interfaces, some intermediate impedance between filter and antenna is optimized to get the desired results. The assembly of both filter and antenna into one module leads to compactness in the RF front-end. The designed filter antenna subsystem has efficiency of 93%.

Investigation of Temperature Effects in Efficiency Improvement of Non-Uniformly Cooled Photovoltaic Cells

This study investigates the performance of photovoltaic (PV) modules with respect to temperature ... more This study investigates the performance of photovoltaic (PV) modules with respect to temperature and proposes pipe layouts enabling efficient cooling. The operating temperatures of the PV cells are not equal since the fluid flowing through the cooling pipes has a temperature difference between the inlet and the outlet of the pipes. The warm atmosphere affects the current density/voltage J/V characteristics of the PV modules. Therefore, the PV cells under cooling tend to operate at a relatively lower temperature resulting in an enhancement in their efficiencies. This paper calculates the J/V characteristics of each PV cell depending on its operating temperature. Then the overall J/V characteristics of the PV module are recorded. The module is cooled by a fluid flowing through pipes underneath the PV module backside. The fluid serves as both heat sink and solar heat collector. In contrast to the existing models, where a PV module and its PV cells are assumed to be having the same oper...

A high quality/low computational cost technique for block matching motion estimation

Designers' Forum: Design, Automation and Test in Europe Conference and Exhibition, 2005

Motion estimation is the most critical process in video coding systems. First of all, it has a de... more Motion estimation is the most critical process in video coding systems. First of all, it has a definitive impact on the rate-distortion performance given by the video encoder. Secondly, it is the most computationally intensive process within the encoding loop. For these reasons, the design of high-performance low-cost motion estimators is a crucial task in the video compression field. An adaptive cost block matching (ACBM) motion estimation technique is presented in this paper, featuring an excellent tradeoff between the quality of the reconstructed video sequences and the computational effort. Simulation results demonstrate that the ACBM algorithm achieves a slight better rate-distortion performance than the one given by the well-known full search algorithm block matching algorithm with reductions of up to 95% in the computational load.

Confidence Intervals Verification for Simulated Error Rate Performance of Wireless Communication System

Wireless Personal Communications, 2012

ABSTRACT In this paper, we derived an efficient simulation method to evaluate the error rate of w... more ABSTRACT In this paper, we derived an efficient simulation method to evaluate the error rate of wireless communication system. Coherent binary phase-shift keying system is considered with imperfect channel phase recovery. The results presented demonstrate the system performance under very realistic Nakagami-m fading and additive white Gaussian noise channel. On the other hand, the accuracy of the obtained results is verified through running the simulation under a good confidence interval reliability of 95 %. We see that as the number of simulation runs N increases, the simulated error rate becomes closer to the actual one and the confidence interval difference reduces. Hence our results are expected to be of significant practical use for such scenarios.

An Improved Dictionary Cracking Scheme Based on Multiple GPUs for Wi-Fi Network

Computers, Materials & Continua, 2021

The Internet has penetrated all aspects of human society and has promoted social progress. Cyber-... more The Internet has penetrated all aspects of human society and has promoted social progress. Cyber-crimes in many forms are commonplace and are dangerous to society and national security. Cybersecurity has become a major concern for citizens and governments. The Internet functions and software applications play a vital role in cybersecurity research and practice. Most of the cyber-attacks are based on exploits in system or application software. It is of utmost urgency to investigate software security problems. The demand for Wi-Fi applications is proliferating but the security problem is growing, requiring an optimal solution from researchers. To overcome the shortcomings of the wired equivalent privacy (WEP) algorithm, the existing literature proposed security schemes for Wi-Fi protected access (WPA)/WPA2. However, in practical applications, the WPA/WPA2 scheme still has some weaknesses that attackers exploit. To destroy a WPA/WPA2 security, it is necessary to get a PSK pre-shared key in pre-shared key mode, or an MSK master session key in the authentication mode. Brute-force cracking attacks can get a phase-shift keying (PSK) or a minimum shift keying (MSK). In real-world applications, many wireless local area networks (LANs) use the pre-shared key mode. Therefore, brute-force cracking of WPA/WPA2-PSK is important in that context. This article proposes a new mechanism to crack the Wi-Fi password using a graphical processing unit (GPU) and enhances the efficiency through parallel computing of multiple GPU chips. Experimental results show that the proposed algorithm is effective and provides a procedure to enhance the security of Wi-Fi networks.

Interference Analysis for Vehicle-to-Vehicle Communications at 28 GHz

Electronics, 2020

High capacity and ultra-reliable vehicular communication are going to be important aspects of bey... more High capacity and ultra-reliable vehicular communication are going to be important aspects of beyond 5G communication networks. However, the vehicular communication problem becomes complex at a large scale when vehicles are roaming on the road, while simultaneously communicating with each other. Moreover, at higher frequencies (like 28 GHz), the dynamics of vehicular communication completely shift towards unpredictability and low-reliability. These factors may result in high packet error and a large amount of interference, resulting in regular disruptions in communications. A thorough understanding of performance variations is the key to moving towards the next generation of vehicular networks. With this intent, this article aims to provide a comprehensive interference analysis, wherein the closed-form expressions of packet error probability (PEP) and ergodic capacity are derived. Using the expression of the PEP, diversity analysis is provided which unveils the impact of channel non...

An Efficient Resource Allocation Algorithm for D2D Communications Based on NOMA

IEEE Access, 2019

The performance of the future mobile communication system could greatly improve as a result of De... more The performance of the future mobile communication system could greatly improve as a result of Device-to-Device (D2D) communication and Non-Orthogonal Multiple Access (NOMA). Reduction of the interference between the D2D users and cellular users is crucial in improving the overall throughput and efficiency of the D2D communication based on NOMA. This paper proposes a joint sub-channel and power allocation algorithm for D2D communication based on NOMA to maximize the uplink energy efficiency and throughput of the mobile communication system. The algorithm uses the Kuhn-Munkres (KM) technique to allocate a channel for each D2D group and formulates an optimal power allocation problem using Karush-Kuhn-Tucker (KKT) conditions. Simulations indicate that the proposed algorithm outperforms the current state-of-the-art algorithms in regards to energy efficiency and throughput under different network conditions.

An Efficient Neighbor Discovery Scheme for Mobile WSN

IEEE Access, 2018

Mobile low-duty-cycle wireless sensor network (MLDC-WSN) is a new type of WSN that has emerged in... more Mobile low-duty-cycle wireless sensor network (MLDC-WSN) is a new type of WSN that has emerged in recent years. It can deploy nodes on moving objects and use the object mobility to capture a wide range of dynamic environmental information. It has diverse applications and has the ability of mobility and gets into sleep for a long time. However, the mobility and sleeping features of MLDC-WSN nodes result in dynamic network topology changes, which restricts discovering their neighbor nodes quickly. Thus, the optimal distribution decision is not established by the nodes. To solve this problem, in this paper, a novel selectively proactive neighbor discovery algorithm is proposed. The proposed algorithm enables the nodes when they wake up to search their neighbor nodes, which prevent the long-time waiting delay in the traditional passive neighbor discovery mechanism. Moreover, the proposed algorithm can further reduce the delay and acquire the accurate neighbor discovery results by quickly determining the next neighbor set at the next moment due to the prediction of the movement speed and distance of neighbors. The analytical and simulation results show that the proposed algorithm can effectively reduce the network energy consumption and delay and can determine all the neighbor nodes quickly and accurately as compared with the existing algorithms. INDEX TERMS WSN, energy efficient nodes, delay, network optimization, adaptive topology.

A MIMO antenna system with high isolation for smart phone applications

2015 Loughborough Antennas & Propagation Conference (LAPC), 2015

In this paper a new compact planar monopole-like multiple-input-multiple-output (MIMO) handset an... more In this paper a new compact planar monopole-like multiple-input-multiple-output (MIMO) handset antenna is proposed. The antenna system consists of two identical antennas with a defected ground arrangement for low correlation and high isolation characteristics. The antennas are oriented horizontally at the no-ground portion located at the top and bottom of the FR4 50 × 102 mm 2 circuit board. The proposed system operates at the 2.3 GHz (2.13-2.64 GHz), 3.6 GHz (3.11-4.83 GHz), and 5.6 GHz (5.15-7.62 GHz) bands. The isolation maintained is better than 18 dB over the desired frequency bands, resulting in an envelope correlation coefficient of less than 0.025. The simulated and measured S-parameters show good agreement. Due to the compact size, the proposed MIMO antenna system is suitable for smart phone applications that have size limitations.

Low correlation multiple antenna system for mobile phone applications using novel decoupling slots in ground plane

2013 Loughborough Antennas & Propagation Conference (LAPC), 2013

A compact low profile multiple antenna system for multiple-input-multiple-output (MIMO) applicati... more A compact low profile multiple antenna system for multiple-input-multiple-output (MIMO) applications is proposed. The antenna system combines two monopole type printed antennas with a slotted ground plane for low correlation and high isolation characteristics. The main antenna covers the twelve wireless communication bands required for LTE, GSM, UMTS2110, Bluetooth, WiMAX and WLAN. The auxiliary antenna has a very small volume compared to the main one and covers the ultra-wideband (UWB) frequency range (3.74-12 GHz). The antennas are positioned at opposite ends of the system's ground in order to reduce the mutual coupling between them. The isolation maintained is better than 20 dB over the desired frequency bands, resulting in an envelope correlation coefficient of less than 0.08. The simulation results show good Sparameters, high gain and radiation efficiency, and relatively stable radiation patterns. Due to the compact size and the ultrawide bandwidth, the proposed multiple antenna system is suitable for communication handsets that have size limitations. Results are presented and discussed.

Low-Profile Frequency Reconfigurable Antenna for Heterogeneous Wireless Systems

Electronics, 2019

A low-profile (0.21 λ g × 0.35 λ g × 0.02 λ g ) and a simply-structured frequency-switchable ante... more A low-profile (0.21 λ g × 0.35 λ g × 0.02 λ g ) and a simply-structured frequency-switchable antenna with eight frequency choices is presented in this paper. The radiating structure (monopole) is printed on a 1.6-mm thicker, commercially-available substrate of FR-4 ( ϵ r = 4.4, tan δ = 0.020). Specifically, it uses three PIN diodes in the designated places to shift the resonant bands of the antenna. The antenna operates at four different modes depending on the ON and OFF states of the PIN diodes. While in each mode, the antenna covers two unique frequencies (Mode 1 = 1.8 and 3.29 GHz, Mode 2 = 2.23 and 3.9 GHz, Mode 3 = 2.4 and 4.55 GHz, and Mode 4 = 2.78 and 5.54 GHz). The performance results show that the proposed antenna scheme explores significant gain (>1.5 dBi in all modes) and reasonable efficiency (>82% in all modes) for each mode. Using a high-frequency structure simulator (HFSS), the switchable antenna is designed and optimized. The fabricated model along with the PI...

A Semi-Automated User-Centric Decision System for Green Communications Incorporating the Particle Swarm Optimization Algorithm

2019 International Symposium on Networks, Computers and Communications (ISNCC)

In the general domain of telecommunications and networking, there is a relatively new area of gre... more In the general domain of telecommunications and networking, there is a relatively new area of green communications techniques that has been attracting the attention of many researchers. It is focused on making communications and network systems more friendly to the environment. In this paper, we aim to control the demand side of a wireless communications system and deploy techniques for shaping it to reduce the load on the network and to improve the capacity. This is due to the fact that wireless infrastructure, such as base stations, switching centers already consume about 0.5% of the global electric power that cause the carbon emissions, which translates into a carbon footprint of 34g of CO2for 1 Mbit of transmitted data. We consider a semi-automated decision system that implements a User-in- The-Loop (UIL) approach that has been described in the literature in recent years, where in addition we deploy the particle swarm optimization (PSO) algorithm in conjunction with two types of user traffic classes, namely, the Best Effort users and the Guaranteed Bit Rate users to enhance the efficient utilization of the overall system resources. Simulation results validate that these suggested UIL solutions techniques can improve the user capacity of the overall system when compared with the traditional uncontrolled system. Hence, this will have a positive impact on the interactions of communications systems with the environment, ultimately achieving the end purpose of the green mobile data communications.

A Novel Broadband Antenna Design for 5G Applications

Computers, Materials & Continua, 2021

Wireless communication is one of the rapidly-growing elds of the communication industry. This con... more Wireless communication is one of the rapidly-growing elds of the communication industry. This continuous growth motivates the antenna community to design new radiating structures to meet the needs of the market. The 5G wireless communication has received a lot of attention from both academia and industry and signi cant efforts have been made to improve different aspects, such as data rate, latency, mobility, reliability and QoS. Antenna design has received renewed attention in the last decade due to its potential applications in 5G, IoT, mmWave, and massive MIMO. This paper proposes a novel design of broadband antenna for 5G mmWave and optical communication networks. It is a hybrid structure that works for both spectrums and contains an absorption dielectric material with an electrical large size. A hybrid transmission line theory ray-tracing technique is proposed ef cient and rapid simulation and optimization of the proposed antenna design. The operating frequency and wavelength of the proposed antenna are 28 GHz in the mmWave band and 1550 nm for the optical spectrum. The spatial frequency is 30 lp/mm when the contrast transfer function is reduced to 0.7 for the optical signal. The effective focal length and aperture are 816.86 and 200 mm. The half-power beamwidth is 3.29 • and the gain is 32.97 dBi for the mmWave band. Simulation results show that the proposed hybrid antenna can effectively be deployed simultaneously for both optical and mmWave 5G communication networks.

Ultra Wideband Wearable Antenna

2019 8th Asia-Pacific Conference on Antennas and Propagation (APCAP), 2019

In this paper, a design approach of an Ultra-Wide Band microstrip patch antenna with decent perfo... more In this paper, a design approach of an Ultra-Wide Band microstrip patch antenna with decent performance and low SAR results is presented. The proposed antenna consists of conducting circular patch element etched on a dielectric printed circuit board with compact size 40×40×1.4 mm3. The design is wearable for on-body applications, flexible, light weight and suitable for 1.8 GHz DCS, 3.6/5.2 GHz WLAN and 5.8 GHz WiMAX.

An Array of M-Shaped Vivaldi Antennas for Uwb Applications

Progress In Electromagnetics Research Letters, 2017

In this paper, a novel M-shaped UWB Vivaldi array antenna is presented. First of all, a simple M-... more In this paper, a novel M-shaped UWB Vivaldi array antenna is presented. First of all, a simple M-shaped UWB Vivaldi antenna is designed, and its properties of return loss, radiation pattern, VSWR, gain, etc. are analyzed. An array of M-shaped UWB antenna is simulated and designed after the successful implementation of the simple UWB Vivaldi antenna. The designed antenna has operating frequency from 3.25 GHz to 8.85 GHz covering 5.6 GHz bandwidth. The antenna has flat gain over entire frequency range. The proposed antenna is fabricated on a commercially available FR-4 substrate having relative permittivity of 4.4 and height of 1 mm. The proposed antenna has wide band and good flat gain over entire frequency range. The proposed antenna can be used in next generation wireless communication because of its efficiency, gain and wide bandwidth.

A Hybrid Energy Harvesting Design for On-Body Internet-of-Things (IoT) Networks

Sensors, 2020

The Internet-of-things (IoT) has been gradually paving the way for the pervasive connectivity of ... more The Internet-of-things (IoT) has been gradually paving the way for the pervasive connectivity of wireless networks. Due to the ability to connect a number of devices to the Internet, many applications of IoT networks have recently been proposed. Though these applications range from industrial automation to smart homes, healthcare applications are the most critical. Providing reliable connectivity among wearables and other monitoring devices is one of the major tasks of such healthcare networks. The main source of power for such low-powered IoT devices is the batteries, which have a limited lifetime and need to be replaced or recharged periodically. In order to improve their lifecycle, one of the most promising proposals is to harvest energy from the ambient resources in the environment. For this purpose, we designed an energy harvesting protocol that harvests energy from two ambient energy sources, namely radio frequency (RF) at 2.4 GHz and thermal energy. A rectenna is used to harv...

Efficient Power Control Framework for Small-Cell Heterogeneous Networks

Sensors, 2020

Heterogeneous networks are rapidly emerging as one of the key enablers of beyond fifth-generation... more Heterogeneous networks are rapidly emerging as one of the key enablers of beyond fifth-generation (5G) wireless networks. It is gradually becoming clear to the network operators that existing cellular networks may not be able to support the traffic demands of the future. Thus, there is an upsurge in the interest of efficiently deploying small-cell networks for accommodating a growing number of user equipment (UEs). This work further extends the state-of-the-art by proposing an optimization framework for reducing the power consumption of small-cell base stations (BSs). Specifically, a novel algorithm has been proposed which dynamically switches off the redundant small-cell BSs based on the traffic demands of the network. Due to the dynamicity of the formulated problem, a new UE admission control policy has been presented when the problem becomes infeasible to solve. To validate the effectiveness of the proposed solution, the simulation results are compared with conventional technique...

Computer simulated assessment of radio frequency electromagnetic waves for the detection of obstructive sleep apnea

Informatics in Medicine Unlocked, 2019

Obstructive sleep apnea/hypopnea syndrome (OSAHS) is the most common form of sleep-disorder breat... more Obstructive sleep apnea/hypopnea syndrome (OSAHS) is the most common form of sleep-disorder breathing (SDB). Recurring restriction or occlusion of the upper airway throughout the night concurrent with continued respiratory efforts lasting more than 10 s characterizes the disorder. Prevalence of OSAHS is increasing globally, with a high association with obesity, hypertension, and heart failure. Nocturnal polysomnography (NPSG), which is the gold standard for OSAHS diagnosis, is scarce, expensive, and cumbersome. Methods for home screening and diagnosis of the disorder, directly and indirectly, are highly sought after to amend or replace NPSG. Well-established norms and procedures for electromagnetic (EM) antenna design, radiation pattern and characterization, and signal reception and measurements can be employed for the direct detection of upper airway occlusion. The utilization of radio-frequency (RF) EM antennas is desirable, as it is inexpensive, and simple to design and implement. In this paper, a computerized simulation of a new EM sensing system for direct detection of the occlusion in the upper airway is presented. Electromagnetic, anatomical, and RF safety constraints are taken into consideration. The theoretical basis of EM, antenna design, and physiological interactions with EM waves are presented. The proposed methodology for creating an anatomically-correct neck and airway simulated phantoms to test the hypothesis and the results of the tests are presented. Hypothesis: Radio-frequency electromagnetic waves transmitted through an open airway will have different energy levels at the distal side of the neck compared to those associated with a fully occluded airway. Methodology: A system is designed comprising a simulated phantom model of the upper airway and neck with the approximate anatomical dimensions and dielectric properties of homogenous neck tissue. Additionally, an RF patch antenna is designed and matched to the phantom neck. An iterative process is developed and implemented for the patch antenna design and coupling with a tissue. Simulation of the EM wave propagation and dissipation throughout the neck in the open and closed airway cases is provided and calculated based on the specific absorption ratios (SAR). The results of several permutations of antenna orientation with respect to the neck and several gaps between the antenna and the neck are provided. Results: the Computer simulations for all antenna orientation and location have shown that the EM energy levels recorded from open airway phantom models are statistically different and lower than those recorded from the occluded airway phantom models. Conclusions: The results of this study support the hypothesis that it is theoretically feasible to use electromagnetic energy to distinguish between open and occluded upper airway.

Simulated topology of doubly powered asynchronous motor with diode clamped inverter

International Journal of Power Electronics, 2019

This paper deals with the problem of modelling, control and analysis of a doubly-powered inductio... more This paper deals with the problem of modelling, control and analysis of a doubly-powered induction machine (DPIM) using a three-level three-phase voltage source inverter known simply as diode clamped inverter (DCI) with a three-phase diode rectifier and a DC link in between. A mathematical model of DPIM and the associated DCI circuit is developed. The stator circuit of the DPIM is supplied directly from an ac system network while its rotor side is supplied via a variable frequency DCI. A multi-loop nonlinear field controller is developed to meet an accurate motor speed, regulation of the mechanical load torque and the overall system power. The results obtained from the simulation in the environment of Simplorer 7 show that the proposed DCI inverter offers great optimisation, little overshoot, and reduced voltage ripples. Consequently, the dynamic behaviour of the motor and the energy efficiency of the overall system are progressively improved and a complete suppress of the influence of the variation in the motor load on the speed of the motor is achieved.

A Multiband and Omnidirectional, CPW-Fed Single-Layer Based Dual Tapered-Slot Antenna

Progress In Electromagnetics Research C, 2016

Travelling wave antennas such as Vivaldi antenna have conventionally been used for obtaining wide... more Travelling wave antennas such as Vivaldi antenna have conventionally been used for obtaining wideband and directional radiation pattern. This paper presents a novel way to obtain first of its kind, omnidirectional travelling wave antenna inspired by Vivaldi. Traditional omnidirectional antennas such as monopole and dipole rely on resonance condition which is usually satisfied on narrow band while the proposed antenna is relatively broadband owing to its travelling wave phenomenon. Moreover, typical Vivaldi antennas are double layered while our design requires only one layer. Antenna has been simulated and optimized in HFSS to operate in dual bands of UWB spectrum. The antenna has been measured and characterized using Keysight handheld VNA and Satimo Anechoic chamber. Good agreement between simulations and measurements has been obtained despite the fabrication tolerance of LPKF PCB manufacturing machine.

Design of compact and miniaturize asymmetric SIR-DRA filter-antenna subsystem

Journal of Electromagnetic Waves and Applications, 2016

The proposed work presents a compact filter-antenna subsystem design using asymmetric stepped imp... more The proposed work presents a compact filter-antenna subsystem design using asymmetric stepped impedance resonator filter and cylindrical dielectric resonator antenna. A cylindrical dielectric resonator antenna is excited from stepped impedance resonator through slot. The DRA is excited for HEM 11 mode. Rather than utilizing customary 50 Ω interfaces, some intermediate impedance between filter and antenna is optimized to get the desired results. The assembly of both filter and antenna into one module leads to compactness in the RF front-end. The designed filter antenna subsystem has efficiency of 93%.

Investigation of Temperature Effects in Efficiency Improvement of Non-Uniformly Cooled Photovoltaic Cells

This study investigates the performance of photovoltaic (PV) modules with respect to temperature ... more This study investigates the performance of photovoltaic (PV) modules with respect to temperature and proposes pipe layouts enabling efficient cooling. The operating temperatures of the PV cells are not equal since the fluid flowing through the cooling pipes has a temperature difference between the inlet and the outlet of the pipes. The warm atmosphere affects the current density/voltage J/V characteristics of the PV modules. Therefore, the PV cells under cooling tend to operate at a relatively lower temperature resulting in an enhancement in their efficiencies. This paper calculates the J/V characteristics of each PV cell depending on its operating temperature. Then the overall J/V characteristics of the PV module are recorded. The module is cooled by a fluid flowing through pipes underneath the PV module backside. The fluid serves as both heat sink and solar heat collector. In contrast to the existing models, where a PV module and its PV cells are assumed to be having the same oper...

A high quality/low computational cost technique for block matching motion estimation

Designers' Forum: Design, Automation and Test in Europe Conference and Exhibition, 2005

Motion estimation is the most critical process in video coding systems. First of all, it has a de... more Motion estimation is the most critical process in video coding systems. First of all, it has a definitive impact on the rate-distortion performance given by the video encoder. Secondly, it is the most computationally intensive process within the encoding loop. For these reasons, the design of high-performance low-cost motion estimators is a crucial task in the video compression field. An adaptive cost block matching (ACBM) motion estimation technique is presented in this paper, featuring an excellent tradeoff between the quality of the reconstructed video sequences and the computational effort. Simulation results demonstrate that the ACBM algorithm achieves a slight better rate-distortion performance than the one given by the well-known full search algorithm block matching algorithm with reductions of up to 95% in the computational load.

Confidence Intervals Verification for Simulated Error Rate Performance of Wireless Communication System

Wireless Personal Communications, 2012

ABSTRACT In this paper, we derived an efficient simulation method to evaluate the error rate of w... more ABSTRACT In this paper, we derived an efficient simulation method to evaluate the error rate of wireless communication system. Coherent binary phase-shift keying system is considered with imperfect channel phase recovery. The results presented demonstrate the system performance under very realistic Nakagami-m fading and additive white Gaussian noise channel. On the other hand, the accuracy of the obtained results is verified through running the simulation under a good confidence interval reliability of 95 %. We see that as the number of simulation runs N increases, the simulated error rate becomes closer to the actual one and the confidence interval difference reduces. Hence our results are expected to be of significant practical use for such scenarios.

An Improved Dictionary Cracking Scheme Based on Multiple GPUs for Wi-Fi Network

Computers, Materials & Continua, 2021

The Internet has penetrated all aspects of human society and has promoted social progress. Cyber-... more The Internet has penetrated all aspects of human society and has promoted social progress. Cyber-crimes in many forms are commonplace and are dangerous to society and national security. Cybersecurity has become a major concern for citizens and governments. The Internet functions and software applications play a vital role in cybersecurity research and practice. Most of the cyber-attacks are based on exploits in system or application software. It is of utmost urgency to investigate software security problems. The demand for Wi-Fi applications is proliferating but the security problem is growing, requiring an optimal solution from researchers. To overcome the shortcomings of the wired equivalent privacy (WEP) algorithm, the existing literature proposed security schemes for Wi-Fi protected access (WPA)/WPA2. However, in practical applications, the WPA/WPA2 scheme still has some weaknesses that attackers exploit. To destroy a WPA/WPA2 security, it is necessary to get a PSK pre-shared key in pre-shared key mode, or an MSK master session key in the authentication mode. Brute-force cracking attacks can get a phase-shift keying (PSK) or a minimum shift keying (MSK). In real-world applications, many wireless local area networks (LANs) use the pre-shared key mode. Therefore, brute-force cracking of WPA/WPA2-PSK is important in that context. This article proposes a new mechanism to crack the Wi-Fi password using a graphical processing unit (GPU) and enhances the efficiency through parallel computing of multiple GPU chips. Experimental results show that the proposed algorithm is effective and provides a procedure to enhance the security of Wi-Fi networks.

Interference Analysis for Vehicle-to-Vehicle Communications at 28 GHz

Electronics, 2020

High capacity and ultra-reliable vehicular communication are going to be important aspects of bey... more High capacity and ultra-reliable vehicular communication are going to be important aspects of beyond 5G communication networks. However, the vehicular communication problem becomes complex at a large scale when vehicles are roaming on the road, while simultaneously communicating with each other. Moreover, at higher frequencies (like 28 GHz), the dynamics of vehicular communication completely shift towards unpredictability and low-reliability. These factors may result in high packet error and a large amount of interference, resulting in regular disruptions in communications. A thorough understanding of performance variations is the key to moving towards the next generation of vehicular networks. With this intent, this article aims to provide a comprehensive interference analysis, wherein the closed-form expressions of packet error probability (PEP) and ergodic capacity are derived. Using the expression of the PEP, diversity analysis is provided which unveils the impact of channel non...

An Efficient Resource Allocation Algorithm for D2D Communications Based on NOMA

IEEE Access, 2019

The performance of the future mobile communication system could greatly improve as a result of De... more The performance of the future mobile communication system could greatly improve as a result of Device-to-Device (D2D) communication and Non-Orthogonal Multiple Access (NOMA). Reduction of the interference between the D2D users and cellular users is crucial in improving the overall throughput and efficiency of the D2D communication based on NOMA. This paper proposes a joint sub-channel and power allocation algorithm for D2D communication based on NOMA to maximize the uplink energy efficiency and throughput of the mobile communication system. The algorithm uses the Kuhn-Munkres (KM) technique to allocate a channel for each D2D group and formulates an optimal power allocation problem using Karush-Kuhn-Tucker (KKT) conditions. Simulations indicate that the proposed algorithm outperforms the current state-of-the-art algorithms in regards to energy efficiency and throughput under different network conditions.

An Efficient Neighbor Discovery Scheme for Mobile WSN

IEEE Access, 2018

Mobile low-duty-cycle wireless sensor network (MLDC-WSN) is a new type of WSN that has emerged in... more Mobile low-duty-cycle wireless sensor network (MLDC-WSN) is a new type of WSN that has emerged in recent years. It can deploy nodes on moving objects and use the object mobility to capture a wide range of dynamic environmental information. It has diverse applications and has the ability of mobility and gets into sleep for a long time. However, the mobility and sleeping features of MLDC-WSN nodes result in dynamic network topology changes, which restricts discovering their neighbor nodes quickly. Thus, the optimal distribution decision is not established by the nodes. To solve this problem, in this paper, a novel selectively proactive neighbor discovery algorithm is proposed. The proposed algorithm enables the nodes when they wake up to search their neighbor nodes, which prevent the long-time waiting delay in the traditional passive neighbor discovery mechanism. Moreover, the proposed algorithm can further reduce the delay and acquire the accurate neighbor discovery results by quickly determining the next neighbor set at the next moment due to the prediction of the movement speed and distance of neighbors. The analytical and simulation results show that the proposed algorithm can effectively reduce the network energy consumption and delay and can determine all the neighbor nodes quickly and accurately as compared with the existing algorithms. INDEX TERMS WSN, energy efficient nodes, delay, network optimization, adaptive topology.

A MIMO antenna system with high isolation for smart phone applications

2015 Loughborough Antennas & Propagation Conference (LAPC), 2015

In this paper a new compact planar monopole-like multiple-input-multiple-output (MIMO) handset an... more In this paper a new compact planar monopole-like multiple-input-multiple-output (MIMO) handset antenna is proposed. The antenna system consists of two identical antennas with a defected ground arrangement for low correlation and high isolation characteristics. The antennas are oriented horizontally at the no-ground portion located at the top and bottom of the FR4 50 × 102 mm 2 circuit board. The proposed system operates at the 2.3 GHz (2.13-2.64 GHz), 3.6 GHz (3.11-4.83 GHz), and 5.6 GHz (5.15-7.62 GHz) bands. The isolation maintained is better than 18 dB over the desired frequency bands, resulting in an envelope correlation coefficient of less than 0.025. The simulated and measured S-parameters show good agreement. Due to the compact size, the proposed MIMO antenna system is suitable for smart phone applications that have size limitations.

Low correlation multiple antenna system for mobile phone applications using novel decoupling slots in ground plane

2013 Loughborough Antennas & Propagation Conference (LAPC), 2013

A compact low profile multiple antenna system for multiple-input-multiple-output (MIMO) applicati... more A compact low profile multiple antenna system for multiple-input-multiple-output (MIMO) applications is proposed. The antenna system combines two monopole type printed antennas with a slotted ground plane for low correlation and high isolation characteristics. The main antenna covers the twelve wireless communication bands required for LTE, GSM, UMTS2110, Bluetooth, WiMAX and WLAN. The auxiliary antenna has a very small volume compared to the main one and covers the ultra-wideband (UWB) frequency range (3.74-12 GHz). The antennas are positioned at opposite ends of the system's ground in order to reduce the mutual coupling between them. The isolation maintained is better than 20 dB over the desired frequency bands, resulting in an envelope correlation coefficient of less than 0.08. The simulation results show good Sparameters, high gain and radiation efficiency, and relatively stable radiation patterns. Due to the compact size and the ultrawide bandwidth, the proposed multiple antenna system is suitable for communication handsets that have size limitations. Results are presented and discussed.

Low-Profile Frequency Reconfigurable Antenna for Heterogeneous Wireless Systems

Electronics, 2019

A low-profile (0.21 λ g × 0.35 λ g × 0.02 λ g ) and a simply-structured frequency-switchable ante... more A low-profile (0.21 λ g × 0.35 λ g × 0.02 λ g ) and a simply-structured frequency-switchable antenna with eight frequency choices is presented in this paper. The radiating structure (monopole) is printed on a 1.6-mm thicker, commercially-available substrate of FR-4 ( ϵ r = 4.4, tan δ = 0.020). Specifically, it uses three PIN diodes in the designated places to shift the resonant bands of the antenna. The antenna operates at four different modes depending on the ON and OFF states of the PIN diodes. While in each mode, the antenna covers two unique frequencies (Mode 1 = 1.8 and 3.29 GHz, Mode 2 = 2.23 and 3.9 GHz, Mode 3 = 2.4 and 4.55 GHz, and Mode 4 = 2.78 and 5.54 GHz). The performance results show that the proposed antenna scheme explores significant gain (>1.5 dBi in all modes) and reasonable efficiency (>82% in all modes) for each mode. Using a high-frequency structure simulator (HFSS), the switchable antenna is designed and optimized. The fabricated model along with the PI...

A Semi-Automated User-Centric Decision System for Green Communications Incorporating the Particle Swarm Optimization Algorithm

2019 International Symposium on Networks, Computers and Communications (ISNCC)

In the general domain of telecommunications and networking, there is a relatively new area of gre... more In the general domain of telecommunications and networking, there is a relatively new area of green communications techniques that has been attracting the attention of many researchers. It is focused on making communications and network systems more friendly to the environment. In this paper, we aim to control the demand side of a wireless communications system and deploy techniques for shaping it to reduce the load on the network and to improve the capacity. This is due to the fact that wireless infrastructure, such as base stations, switching centers already consume about 0.5% of the global electric power that cause the carbon emissions, which translates into a carbon footprint of 34g of CO2for 1 Mbit of transmitted data. We consider a semi-automated decision system that implements a User-in- The-Loop (UIL) approach that has been described in the literature in recent years, where in addition we deploy the particle swarm optimization (PSO) algorithm in conjunction with two types of user traffic classes, namely, the Best Effort users and the Guaranteed Bit Rate users to enhance the efficient utilization of the overall system resources. Simulation results validate that these suggested UIL solutions techniques can improve the user capacity of the overall system when compared with the traditional uncontrolled system. Hence, this will have a positive impact on the interactions of communications systems with the environment, ultimately achieving the end purpose of the green mobile data communications.