Most modern wideband Direction of Arrival (DOA) estimation methods report reasonable resolution at the expenses of high computational complexity. In this paper, an enhanced approach for wideband DOA estimation with high resolution and low computational requirements is introduced. The suggested approach is based on combining the Incoherent Signal Subspace Method (ISSM) with Compressive Sensing (CS). The CS is employed using deterministic chaotic sensing matrices to decrease the dimension of the measurement vector, and hence reduce the software complexity. The efficiency of the introduced technique in enhancing the DOA estimation efficiency is studied for Uniform Linear Antenna Array (ULA). Several evaluation metrics, including the spatial spectrum, the consumed time, and the Root Mean Square Error (RMSE) between estimated and actual DOAs when varying the Signal to Noise Ratio (SNR) and number of elements, are investigated to assess the performance of the proposed approach. Results reveal that the proposed ISSM with CS succeeds not only to achieve high DOA resolution for separating very closely spaced sources, but also to significantly reduce the computational complexity while keeping nearly the same estimation resolution. This demonstrates the effectiveness of the proposed DOA estimation approach in wideband real-time wireless systems.
Organic inorganic hybrid perovskite solar cells (PSC) showed high performance since their use in photovoltaic industry. Recently, mixed cation perovskites are being studied by many researchers to reach the best composition and efficiency. Triple cation perovskites are characterized by their large band gap tunability which help them be modeled for single and tandem solar cells. In this paper we present solar cell characteristics of Cesium Formamidinium Methylammonium Lead Iodide Bromide Cs0.05 FA0.8 MA 0.15 Pb (I 1-x Br x ) 3 by tunning the band gap absorber layer from (1.54-2.11 eV) at different bromide concentrations using a computational 2D optical and electrical model. The conduction band offset of Electron Transport Layer (ETL) as well as the metal work function of the Contact/Hole Transport Layer (HTL) interface were optimized to reach the best performance. The structure ITO/TiO 2 /CsFAMAPbIBr/CuSCN/Au results in a short circuit current (J sc ) 20.789 mA/cm 2 an open circuit voltage V oc 1.14 V and power conversion efficiency (PCE) of 17.830%.
This paper presents a new type of phased array antenna (PAA) that uses plasma material to achieve circular polarization characteristics. The plasma controls the phase shift of individual elements without the need for conventional phase shifters feeding network. The PAA is made up of 64 plasma dipole elements arranged into $4\times 4$ sub-arrays, each consisting of $2\times 2$ sequentially rotated plasma dipole elements with different plasma ionization frequencies. The PAA is designed to radiate either right-hand circular polarization (RHCP) or left-hand circular polarization (LHCP). Two different sub-array arrangements are designed with plasma frequencies distribution of $(\omega_{\mathrm{p}1},\omega_{\mathrm{p}2},\omega_{\mathrm{p}1},\omega_{\mathrm{p}2})$ for arrangement (I), and $(\omega_{\mathrm{p}1},\omega_{\mathrm{p}2},\omega_{\mathrm{p}^3},\omega_{\mathrm{p}4})$ for arrangement (II). The frequency for minimum axialratio is controlled by selecting $\omega_{\mathrm{p}1}$ , and $\omega_{\mathrm{p}2}$ . PAA is designed to radiate right-hand circular polarization (RHCP) with peak gain of 20.9 dBi, and the 3-dB bandwidth $(\text{AR} < 3\text{dB})$ is 200 MHz. In arrangement (II), PAA radiates left-hand circular polarization (LHCP) with peak gain 19.1 dBi and AR bandwidth of 440 MHz. The NF-focused array focuses the field on a spot width of 4.4 cm compared to 6.6 cm for the non-focused array. A near-field focused PAA is also designed using one of the sub-array arrangements (I). This array focuses the field on a narrower spot compared to the non-focused array.
This research presents a reconfigurable Multi-Beam Directional of Yagi-Uda array for terahertz communications. The structure consists of planar dipole antenna surrounded by rows of metallic patches with graphene sector rings printed on silicon oxide substrate. Controlling the chemical potential of the graphene sectors switch, a single beam in two, four or eight directions. OFF-state $(\mu_{c1}=0eV)$ acts as director and ON-state $(\mu_{c2}=2eV)$ acts as reflector. A parametric study on the influence of adjusting the distance between the driven dipole and the patch sectors and the radius of the copper patches is studied. Adjusting of number of graphene sector rings on the the resonance frequency and peak gain has been investigated. It produces good impedance matching at 2.29 THz with peak gain of 8.19 dBi.
Compressed sensing enables sparse signals recovery from few linear measurements. For many types of signals, such as those which exhibit sparsity in the wavelet domain, the non-zero elements occur in blocks. Signals of this type are referred to as block-sparse signals. This paper proposes a block-sparse signal reconstruction algorithm, block adaptive matching pursuit (BAMP), which is characterized by high speed and accuracy. In this algorithm, a number of blocks is selected in each iteration, which is adapted according to the average correlation between the signal and blocks of the measurement matrix. Moreover, in each iteration, the support is refined, or pruned, to exclude blocks that do not contribute to the signal. We apply BAMP to ECG signal recovery from compressed measurements. Simulations illustrate significant improvements in accuracy and speed in comparison to other related block-sparse recovery algorithms for random and ECG signals.
There has been an increase in interest in free-space optical (FSO) communication over the past decade. The usage of FSO is limited by the weather, despite the fact that it has a wide range of uses in both indoor and outdoor settings. Dust is considered a significant weather limitation that might cause the link to drop. Using real-time data from the Egyptian Meteorological Authority, we first investigate the statistical behavior of the dusty channel in this work before presenting a probability distribution function (PDF) for dust attenuation. Then, a closed formula is employed to express the composite channel state brought on by the suggested dust model and gamma-gamma (G-G) atmospheric turbulence. Moreover, we analyzed the average bit error rate (BER) and normalized capacity theoretically in terms of closed forms to assess the system performance. The results show that the system's performance is significantly impacted by the dust storm.
The use of microbubble (MB) contrast agents and specialized ultrasound (US) techniques during contrast-enhanced ultrasound (CEUS) imaging has been an effective way to visualize blood vessels. Various transmit pulsing and postprocessing schemes are typically used for CEUS imaging to extract the nonlinear MB waveform from the echo signal. However, a new software solution called pulse inversion spectral deconvolution (PISD) has been introduced that can separate tissue and MB signal components without the need for a specific pulse selection. The study detailed herein aims to describe a novel three-dimensional (3-D) PISD-based CEUS imaging system and method. US data was collected using a research scanner (Vantage 256, Verasonics Inc) equipped with a 1024-element matrix array transducer (Vermon) and a vascularized phantom (Model ATS 524, Sun Nuclear) linked serially with a flow pump and mixing chamber filled with a MB contrast agent (Definity, Lantheus Medical Imaging) in water solution. 3-D PISD-based CEUS images were produced offline by custom MATLAB software (Math Works Inc), which involved using a pair of Gaussian derivative functional filters applied to backscattered US channel data before envelope detection and volume reconstruction. A contrast-to-noise ratio (CNR) measure was used to quantify contrast enhancement between PISD and standard B-mode CEUS images of the perfused phantom material. Results showed that 3-D PISD-based CEUS imaging provided a 40 dB increase in vessel enhancement compared to B-mode CEUS images. Overall, these preliminary in vitro findings suggest that 3-D CEUS with PISD postprocessing has potential as a valuable addition to the current vascular imaging techniques.
The typical solar module has numerous drawbacks when used for extended periods of time in environmental conditions. Examples include cracked cells, interconnection failure, and decreasing output power. Also, it cannot be repaired; once a fault occurred in one cell, the module must be replaced. The proliferation of unused solar panels has become an issue due to the vast increase in the use of solar energy resources. While the current focus of solar panel research is to increase production energy efficiency, solar panel repairability and recycling of end of life (EOL) panels is rarely considered. The management of the EOL panels can efficiently save natural resources and save production costs. This study explores conventional encapsulation methods and introduces a novel approach to solar panel design that allows for easy access to individual components, facilitating repairs, upgrades, and modifications. The experimental study demonstrates that when using the novel encapsulation method, illumination current voltage properties are unaffected. Furthermore, a thermal analysis is conducted to compare the performance of the proposed module with the traditional module. It was found that, depending on illumination intensity and ambient temperature, the temperature of the cells inside our module is higher than the traditional by the range of 1K to 5.7K and decrease the power by (−0.65%/ K) of the PV module. However, the proposed method offers advantages in terms of reliability and reparability. In this paper, firstly, the solar system components are introduced. Secondly, proposed the types and resources of solar panel used in the components. Thirdly, proposed the causes of solar PV panel failure. Fourthly, proposed laminated solar panel recycling techniques. Finally, it's suggested a different method of solar module encapsulation to have a way to access and repair or alter any element.
In this paper a general solution for the electromagnetic field that can be obtained inside arbitrarily shaped corrugated waveguide. The excitation is made spatially periodic at the same period as the corrugation, where the corrugation is made as a truncation in a canonical smooth conducting waveguide, such as planar, rectangular, or circular. Floquet canonical modes in smooth waveguide is used as a basis to expand the field solution inside the corrugated structure.
For RF energy harvesting applications, a novel wide-band miniaturised antenna design is presented in this research study. The 1.7 GHz to 2.7 GHz frequency spectrum is harvested using a wide antenna. A ground with a slit and a circular microstrip patch antenna makes up this antenna, which is designed to be smaller and to obtain more gain by reflecting back radiation. At cellular communications and Wi-Fi frequencies of 1.8, 2.1, and 2.4 GHz, respectively, it achieves radiation efficiencies of 96.9%, 98.9%, and 98.8%. The suggested antenna is built on a FR4 substrate with a dielectric constant of 4.4 and has an overall dimension of 40 mm x 50 mm x 1.6 mm. This study presents the design, simulation, and production with good agreement.
The Internet of Things (IoT) has opened up a world of opportunities for improving our daily lives. One offshoot of the IoT is the Internet of Vehicles (IoV), which aims to enhance traffic safety and provide low route information. However, the security of information exchanged between moving vehicles and wireless mediums is crucial. Physical Unclonable Function (PUF) is an effective security technology that creates a hardware fingerprint based on the unique characteristics of a device. The Ring Oscillator (RO) PUF is the most commonly used PUF. This study proposes an enhanced RO PUF design that generates a 64-bit secret key well-suited for IoV applications. The proposed design demonstrates significant improvements in PUF performance, with a uniqueness, reliability, and uniformity of 49.83%, 99.93%, and 49.75%, respectively. These findings suggest that the enhanced RO PUF design provides effective and reliable solutions for securing IoT devices through PUF-based authentication.
The unprecedented growth of massive satellite constellations, as well as the advent of a significant number of steerable beams and digital payloads, poses new challenges in determining how to distribute satellite resources. New resource management strategies that operate in high-dimensional and dynamic environments will be required to meet these new challenges. Under the context of satellite communications, the resource allocation (RA) problem is decomposed into six sub-problems: frequency assignment, power allocation, beam placement, user grouping, gateway routing, and satellite routing. Existing conventional techniques of satellite resource allocation become unfeasible to deal with these new challenges and new algorithms have to be developed. The majority of frequency assignment methods fail to fulfill the requirements of the high-dimensional and dynamic environments without defaulting on bandwidth utilization and power efficiency. The work in this paper proposes a new frequency assignment algorithm based on a mathematical programming language (AMPL) that can completely design a dynamic frequency plan with bearing in mind system constraints like handovers and interference. The proposed algorithm is evaluated with multiple objective functions such as bandwidth maximization and produces optimal solutions. Experimentally, the proposed algorithm can allocate at least 155% more bandwidth compared to previous baseline benchmarks.
This research addresses the challenge of evaluating the capability of an emerging pooling method, namely, wavelet pooling, to increase the data efficiency in deep neural networks. Specifically, we focus on light-weight network architectures. The volume of training data required to achieve a particular performance level, e.g., recognition accuracy, is what we refer to as data efficiency. Recently, wavelet pooling has been attracting an increasing research attention due to its capacity to overcome the spatial information loss that is inherent in traditional pooling, by capitalizing on localized spectral information in the wavelet domain. We proposed a new wavelet pooling approach recently which has shown significant promise specifically on MobileNets. This approach chooses which wavelet band(s) to include during training by matching the input images (to be recognized) to specific wavelet sub-bands, hence the name-Matched Wavelet Pooling (MWP). How does the performance of MobileNets differ when MWP is adopted compared to the performance of baseline MobileNets and MobileNets with non-matched wavelet pooling? The principal contribution of this research is addressing this research question. We hypothesize that MWP when used on MobileNets requires a smaller volume of training, than baseline MobileNets and non-matched wavelet pooling, to achieve the same recognition accuracy. On two popular benchmarks, namely, CINIC-10 and STL-10 datasets, we report consistent data savings (achieved by MWP) that approaches 30% compared to the baseline MobileNet model and the non-matched wavelet pooling while achieving higher recognition accuracy.
Network intrusion detection has an important role in providing security to networks and computer systems. It applies different artificial intelligence technologies in order to improve performance against various cyber-attacks. Applying Deep Learning (DL) techniques has a considerable impact compared to using traditional Machine Learning (ML) methods. Recently, Convolutional Neural Network (CNN) has been widely used by researchers to enhance Intrusion Detection Systems (IDSs). This paper aims to build a customized CNN model to improve the accuracy of IDSs. The study involves comparing the results obtained from the proposed CNN model with those obtained from Random Forest which is a well-known machine learning technique utilized frequently in IDSs. The performance of both models was evaluated using standard measurements such as accuracy and F-measure. Two datasets were used, UNSW-NB15 and CSE-CICIDS2018, to demonstrate the efficacy of our proposed model. The proposed CNN model achieved better results than the Random Forest algorithm. A comparison with existing recent IDSs was carried out. The result of this study provides insights and proves the effectiveness of using CNNs for IDSs and helps in identifying the best approach for building efficient and accurate CNN based IDSs with the accuracy of 99.18% using CSE-CICIDS2018 dataset and 99.70% using UNSW-NB15 dataset.
The most crucial step of a cellular framework's life cycle is radio network design since it determines the system's operational costs (OPEX), capital costs (CAPEX), and long-term viability. Consequently, it is not unexpected that radio planning arranging had been examined broadly for the past three decades for all four eras of cellular frameworks. In this paper, we first provide a brief overview of the major technologies that enable B5G/6G network planning and arrangement requirements, such as capacity estimation, reservation coverage calculation, and dynamic capacity assignment. The B5G/6G air interface and its various propagation models, which are appropriate for the mid and high bands (mmWave) spectrum, are also mentioned. Traffic kinds, propagation modelling, and calculation methods for system throughput and capacity are among the RF essential parameters and planning parameters. This research expects to provide initial planning and radio deployment perspectives description for B5G/6G New Radio (NR) technology implementation in Knowledge city of administrative new capital. Special concern will be investigated due to the nature of having dense urban area as well as the starving for high data rate applications that may be implemented in the smart cites. The advent of B5G/6G technology has facilitated the establishment of smart cities with the necessary connectivity that empowers the utilisation of sensors, data analysis, analytics, and various other related resources. The pivotal role that technology plays in the transformation of urban environments into sustainable, resilient, and efficient entities underscores the importance of this innovative feature in shaping the future of smart cities. Network planning process presented in this paper will be based on coverage area at frequency 2.6 GHz, 3.5 GHz, and 28 GHz in The Knowledge City. Link budget is estimated using an outdoor-to-outdoor (O2O) with Line-of-Sight (LOS) scenarios UMa (Urban Macro-Street canyon) model and Urban Micro (UMi) are being used as standardized propagation model.
In this work, an add/drop micro ring resonator is used to demultiplex eleven frequency lines having a separation of 200 GHz, which are provided by a frequency comb generator. The design of the Si 3 N 4 /SiO 2 TriPleX waveguide structure used for this aim is reported. The waveguide width is 2.2 μm and the heights of the two stacks are 100 and 175 nm for lower and upper layers, respectively. The central frequency of the eleven channels is 193.3 GHz. The ring radii ranges from 40 to 56 μm with the worst crosstalk of 27.23 dB. The validation of the design is executed by FDTD simulation and the S-matrix technique to get the overall response of each ring resonator. The main specifications are set to achieve 3 GHz bandwidth for each channel, reduce the crosstalk between channels, and minimize the radiation losses generated by the rings.
Smart agriculture requires field sensing, especially video and photo transmissions, to detect severe issues in this field. Although the most suitable communication infrastructure is wireless transmission, the agriculture field suffers from severe diffraction and scattering of the wirelessly propagated waves. This paper proposes an optimization technique for improving wireless transmission in the agricultural environment by utilizing the most appropriate wireless impairment mitigation methods. The proposed technique adopts a joint wireless transmission optimization approach for both the client and the network sides. The amendment in the wireless transmission from the client-side perspective utilized the concurrent load balance over the heterogeneous wireless connections. While the refinement of the heterogeneous wireless network achieved better coverage by minimizing the number of propagating nodes by optimizing the propagating nodes' placement within the agricultural plot. The simulation, experiment, and results proved the effectiveness of the proposed solution for achieving better wireless video transmission performance.
This paper presents a design methodology for broadband, high-efficiency power amplifiers, suitable for octave bandwidth. Based on model-based de-embedding of the parasitics associated with packaged GaN-HEMT devices. To construct the input/output matching networks, and depending on the nodal quality factor, the parasitics are fully/partially absorbed in the matching networks, while the excess reactance is resonated out. To verify the proposed approach, a 7-W 3–6 GHz power amplifier is designed and implemented. An average drain efficiency and gain of 50% and 11-dB are achieved, respectively, across the operation bandwidth.
Plasmonic Photovoltaics (PVs) are an effective method for increasing optical absorption by adding metallic nanoparticles to the photovoltaic active layer. The role of these nanoparticles is confining the incident light near them in the PV cell, resulting in thin film PVs of enhanced efficiency. Therefore, different materials and new NPs shapes are used for this purpose. In this research, a step pyramid is introduced as a novel structure for nanoparticles for enhancing plasmonic PVs by embedding an array of the proposed step pyramid nanoparticles within the PV cell. Therefore, the extinction cross-section at different dimensions of the NP is studied. Also, the field modes of the plasmonic PV are studied, showing the confinement of the field around the edges of the proposed NPs. Thus, the proposed structure is a promising candidate for enhancing Photovoltaics performance.
This paper presents the design and analysis of a new method for measuring the phase shift between two microwave signals. The proposed method operates in S and C band applications. It covers the frequency range from 2 GHz to 8 GHz. The configuration of this method is based on distinguishing the reference (REF) and measured device under test (DUT) signals from each other by passing them through two different parallel paths. A reference phase shifter is inserted to achieve the difference between the two paths. The phase shift value of the phase shifter used for this system is designed to be 90° degrees. In each stage of this method, the magnitude of the power level is measured. Their values are used to calculate the phase shift between the REF and measured DUT signals. The system performance and accuracy results are investigated. It shows a maximum phase deviation of $\pm 3.5^{\circ}$ .
