Amirkabir University of TechnologyAUT Journal of Electrical Engineering2588-291058Special Issue 120260501Designing an Efficient Blockchain-Enabled Internet of Things (IoT) framework for Smart Farming316583210.22060/eej.2025.24288.5673ENTsegazewoldKinfuElectrical and Computer Engineering, Hawassa University Institute of Technology(HUIoT), Hawassa, EthiopiaYirgaYayehDepartment of Information Technology, Injibara University, Injibara, Ethiopia, National Yang Ming Chiao Tung University, Taiwan0000-0001-6057-9622YechaleAmogneElectrical and Computer Engineering, Woldia Institute of Technology(WiT), Woldia, Ethiopia0009-0002-9418-2679EmiyamrewAzmerawComputer Engineering, University of Gondar, Gondar, EthiopiaAyodeji OlalekanSalauDepartment of Electrical/Electronics and Computer Engineering, Afe Babalola University, Ado-Ekiti, NigeriaSaveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences, Chennai, Tamil Nadu, India0000-0002-6264-9783Journal Article20250614In recent years, with the development of emerging technologies in developing countries, smart farming and pre- cision agriculture are more and more popular, especially using blockchain Internet of Things (IoT) system. In this study, we pro- pose a four-layer architecture for designing a blockchain-based IoT system in the domain of smart farming. The architecture comprises device nodes, fog nodes, a cloud server, and end users. Hyperledger Fabric is employed as the underlying blockchain framework, ensuring permissioned access and secure data man- agement. Additionally, we incorporate Role-Based Access Con- trol (RBAC) to further enhance security. Through performance analysis, including measures such as throughput and latency, we evaluate the system’s efficiency and responsiveness. The results demonstrate the benefits of using Hyperledger Fabric and a permissioned blockchain approach in smart farming, providing valuable insights for stakeholders and farmers seeking secure and reliable IoT solutions for agricultural practices.https://eej.aut.ac.ir/article_5832_677fa4059ee76333f9bb9a7920aef719.pdfAmirkabir University of TechnologyAUT Journal of Electrical Engineering2588-291058Special Issue 120260501IoT Based Watering System Activation on Smart Garden1726588810.22060/eej.2025.24495.5716ENRini PujiAstutikDepartement Electrical Engineering, Faculty of Engineering, Universitas Muhammadiyah Gresik, Gresik, Indonesia0000-0003-0777-2153BudyGunawanDepartement Electrical Engineering, Faculty of Engineering, Universitas Muhammadiyah Gresik, Gresik, IndonesiaArbi AlfianMas'udDepartement Electrical Engineering, Faculty of Engineering, Universitas Muhammadiyah Gresik, Gresik, IndonesiaJournal Article20250731Watering and maintaining garden plants are essential daily activities for garden owners. However, for busy individuals, this task is often neglected, causing the plants to dry out and eventually die. This study proposes an IoT-based automatic watering system designed to activate irrigation based on soil moisture readings. The system employs soil moisture sensors and the Blynk IoT platform for real-time monitoring and control. The experience results show that the automatic watering mechanism performs more effectively than manual watering, maintaining optimal soil conditions and ensuring plant health. Additionally, user can monitor system status remotely through a smartphone. The proposed system transforms an ordinary garden into a smart garden that support autonomous, efficient, and sustainable plant care.https://eej.aut.ac.ir/article_5888_0a54b19a13b6712dc04d1b49215423d8.pdfAmirkabir University of TechnologyAUT Journal of Electrical Engineering2588-291058Special Issue 120260501High-Precision Direction of Arrival Estimation for Closely Spaced Targets Using Binary-Phase Reconfigurable Intelligent Surfaces and Minimum Redundancy Linear Arrays2738588210.22060/eej.2025.24292.5674ENMeysamRaees DanaeeAssistant Professor, Faculty of Electrical Engineering, Imam Hossein University, Tehran, Iran0000-0001-6693-3565AhmadAtaeiPhD Candidate of Electrical Engineering, Faculty of Electrical Engineering, Imam Hossein University, Tehran, IranJournal Article20250615A novel method for enhancing the accuracy of direction of arrival estimation for two closely spaced targets by optimizing the geometric array configuration of a Binary-Phase Reconfigurable Intelligent Surface based on Minimum Redundancy Linear Arrays is proposed. In Binary-Phase Reconfigurable Intelligent Surfaces, the phases of the reflected signals at the Reconfigurable Intelligent Surfaces elements remain unchanged or undergo a 180-degree phase shift, making it significantly more cost-effective in terms of hardware compared to traditional direction of arrival estimation systems. This cost reduction, however, leads to an increase in the correlation of dictionary atoms. To compensate for this drawback, we regularize the optimization problem using atomic norm. Subsequently, the problem is transformed into its dual form to facilitate solving with existing solvers. Simulation results demonstrate that the proposed method can estimate the direction of arrival with higher accuracy for closely spaced targets in the angular domain, compared to existing Reconfigurable Intelligent Surfaces-based array methods, while maintaining the same hardware complexity.https://eej.aut.ac.ir/article_5882_dffac38df13c3a801f1b8994f9303bcc.pdfAmirkabir University of TechnologyAUT Journal of Electrical Engineering2588-291058Special Issue 120260501Achievable Rate Region for Wireless Multiple Access Channels with UAV Relay and k Independent Transmitters3950598910.22060/eej.2026.23943.5643ENPadidehNobakhtDr, Department of Electrical Engineering, sadjad University, Mashhad, Iran0009-0008-5033-3547Amir MasoudAminian ModarresDr, Department of Electrical Engineering, sadjad University, Mashhad, Iran0000-0002-1180-4106Ghosheh AbedHodtaniProfssor, Department of Electrical Engineering, Ferdowsi University, Mashhad, Iran0000-0002-4337-1624Journal Article20250302This paper considers and characterizes a multiple access relay channel (MARC) with $k$ transmitters, one UAV relay, and a terrestrial receiver, where we derive a new achievable rate region for the continuous alphabet wireless with an unmanned aerial vehicle (UAV) relay. The derived rate region is then evaluated numerically and compared with those of multiple access channels (MAC) and MARC with terrestrial relays. The results show that the presence of a UAV relay increases the achievable rate region of MAC systems by exploiting higher line-of-sight (LoS) channel quality and time-varying spatial link gains due to the UAV’s position. This improvement in the achievable region is not merely due to the UAV’s presence but arises from the different channel geometry and dynamic link conditions introduced by the UAV relay compared with terrestrial relays.https://eej.aut.ac.ir/article_5989_1ae6464c6b5d51b363d7d96f97132c75.pdfAmirkabir University of TechnologyAUT Journal of Electrical Engineering2588-291058Special Issue 120260501The Upper-Bound of the Average Achievable Rate of Non Orthogonal Multiple Access5158591410.22060/eej.2025.24031.5647ENMinaBaghaniPhD, Faculty of Technical and Engineering, Imam Khomeini International University, Qazvin,
Iran0000-0001-5806-6043Journal Article20250404The Non Orthogonal Multiple Access (NOMA) is a popular candidate for the next generation of wireless networks. Two advantages of NOMA are that it can achieve a higher rate and support more users compared to orthogonal multiple access (OMA). By increasing the number of users occupied a subchannel in NOMA, the achievable rate and the number of supported users of the system have been increased. Thus, we can assume there are infinite users in the system wanting to share one subchannel to derive the upper bound of the achievable rate of NOMA. In this article, the optimal power allocation function of infinite users in NOMAis derived, which maximizes the average achievable rate of the system under the maximum power constraint. The performances of the proposed power allocation strategy are compared with the simple case with only two users in NOMA. The simulation results show the gap between the average achievable rate and the outage probability of infinite users and two users in the NOMA system.https://eej.aut.ac.ir/article_5914_dd5bfdeb57f7c75d400de61e99d78e2e.pdfAmirkabir University of TechnologyAUT Journal of Electrical Engineering2588-291058Special Issue 120260501Advancing massive MIMO mm-Wave Channel Estimation by Coherence-Optimized Measurement Matrices5970564210.22060/eej.2025.23570.5625ENMeysamRaees DanaeeAssistant professor, Department of Electrical Engineering, IHCU, Theran, Iran0000-0001-6693-3565Journal Article20240930In the realm of millimeter-wave (mmWave) communications, despite their promise of high data rates and expansive bandwidths, channel estimation encounters formidable challenges due to conspicuous path loss and the limited multipath components. This paper presents an innovative method that leverages the inherent sparsity of mmWave channels by operating within the two-dimensional transformed domain, this approach treats the channel as a sparse image representation. We advance the accuracy of sparse equivalent vectorized channel recovery by optimizing the measurement matrix. The proposed optimization method significantly reduces the requisite measurements and accelerates the estimation process and minimizes the mean squared error between the true and estimated channel matrices. Through comprehensive simulations, we evaluate our method against two scenarios: one where the compression rate is zero, and the sparse channel matrix recovery relies on the number of observations equating the number of channel matrix elements, and another where the compression rate is non-zero, but the measurement matrix remains unoptimized and randomly selected. Results demonstrate that our method outperforms the latter scenario and achieves accuracy comparable to the former, with significantly reduced computational overhead and accelerated computation speed.https://eej.aut.ac.ir/article_5642_754c32eb39c6dfd8b7c97531a459937c.pdfAmirkabir University of TechnologyAUT Journal of Electrical Engineering2588-291058Special Issue 120260501Performance Analysis of Local Processors-Assisted Cell-Free massive Multiple Input Multiple Output Systems7184579410.22060/eej.2025.23871.5640ENRezaRoshanghiasDepartment of Electrical Engineering, Yazd University, Yazd, Iran0009-0000-5620-6989RezaSaadatDepartment of Electrical Engineering, Yazd University, Yazd, IranSaeedGazorDepartment of Electrical and Computer Engineering, Queen's University, Kingston, CanadaJournal Article20250202This paper proposes a local processors-assisted structure (LPs-AS) for cell-free massive multiple-input multiple-output (CF-mMIMO) systems, consisting of a central processor (CP), several access points (APs), and some local processors (LPs). Each LP is connected to the CP and a subset of APs and is used as a precoding unit in downlink (DL). This proposed LPs-AS enables us to implement DL precoders with a semi-distributed approach. In our proposed semi-distributed implementation (SDI), we design precoders at the LPs. This approach differs from centralized implementation (CI) where the precoders are implemented at the CP and distributed implementation (DI) where the precoders are designed at the APs. We evaluate LPs-AS in terms of spectral efficiency (SE) and analytically derive its achievable SE. Furthermore, we propose a power control algorithm to maximize its sum SE, compute the computational complexity (CC) of its minimum mean square error (MMSE) precoders, and compare this CC with its counterpart in CI and DI. Numerical results demonstrate that employing an optimal number of LPs (between 2 and 4) in our proposed LPs-AS, not only enables us to design DL precoders with significantly low CC but also results in an efficient SDI that effectively addresses the problem of low SE in DI.https://eej.aut.ac.ir/article_5794_5d55e7c13b0f4d7cf9d5d55d3af329c8.pdfAmirkabir University of TechnologyAUT Journal of Electrical Engineering2588-291058Special Issue 120260501Potential Impacts of Radiofrequency Electromagnetic Fields on the Central Nervous System, Brain Neurotransmitter Dynamics and Reproductive System85104573410.22060/eej.2025.23753.5631ENMehrshadEskandarpourBSc, Electrical Engineering, Telecommunication Systems and Networks, IUST, Tehran, Iran0009-0006-8597-0293AmirsamanNooraminAssistant Professor, Electrical Engineering, Telecommunication Fields and Waves, IUST, Tehran, Iran0000-0002-3853-9824Journal Article20241215Human life has been increasingly affected by the rapid advancement of electronic technology and the widespread use of devices emitting electromagnetic radiation (EMR), such as Wi-Fi and mobile phones. While much remains unclear, studies suggest that electromagnetic fields (EMFs) can influence human health, particularly reproduction and the nervous system. EMF exposure, including from non-ionizing radiation produced by Wi-Fi and mobile phones, has been linked to potential effects on the male and female reproductive systems, embryonic development, and neuronal health. Key mechanisms include oxidative stress, thermal effects, changes in neurotransmitter metabolism, receptor function, nerve cell apoptosis, and ion channel dynamics. However, the long-term health risks, especially in children and adolescents due to prolonged exposure, remain a topic of debate. Despite current studies not confirming that RF-EMW from Wi-Fi exceeds safety guidelines, further research is essential to fully understand the implications of RF-EMW exposure on human health, particularly regarding reproduction and neurological effects. This review highlights the need for updated safety standards, more refined regulatory frameworks, and long-term investigations to clarify the potential biological and neurobiological consequences of EMF exposure.https://eej.aut.ac.ir/article_5734_860052df4915de4d6c3deac9f7ebf5cc.pdfAmirkabir University of TechnologyAUT Journal of Electrical Engineering2588-291058Special Issue 120260501Design and Implementation of a Wideband Antenna for Simultaneous Receiving and Transmitting Signal with an Improved Isolation105112589510.22060/eej.2025.23986.5644ENAbbasSabeti AghdamDepartment of Electrical Engineering, Amirkabir University of Technology, Tehran, Iran0009-0007-4377-5307GholamrezaMoradiDepartment of Electrical Engineering, Amirkabir University of Technology, Tehran, Iran0000-0002-2779-0175Journal Article20250310This paper proposes a dual-layer, microstrip patch antenna for simultaneous sending and receiving in the telecommunications industry. In this design, the harmonic suppression method is used. The proposed antenna has two ports with improved isolation and combines several telecommunication elements, including filters, duplexers, and radiators, into a single device, which reduces size, weight, and cost. The proposed antenna is designed, fabricated, and measured at C-band to verify and design methodology. The measurement results agree with the simulation results, which represent a complete two-way antenna in the frequency bands of (4.56-5) GHz (9.2%) and (6.25-7.39) GHz (16.8%) with an isolation of over 33 dB. The proposed antenna gain for the first and second bands is 5.6 dBi and 6.3 dBi, and the 3-dB beamwidths in two frequencies (f = 4.8 GHz and f = 6.8 GHz) are 83° and 85°, and the cross-polarization levels are −22 and −23 dB in the E- and H-planes, respectively. The antenna exhibits pure linear polarization with minimal cross-polarization levels observed in both E- and H-planes.https://eej.aut.ac.ir/article_5895_33853141e0873909be88f5c3e6144cc6.pdfAmirkabir University of TechnologyAUT Journal of Electrical Engineering2588-291058Special Issue 120260501Breaking Probabilistic Side-Channel Defenses: A Deep Learning Approach to Cryptographic Key Recovery604210.22060/eej.2026.24478.5712ENMehrshadEskandarpourElectrical Engineering, Telecommunication Networks, IUST, Tehran, Iran0009-0006-8597-0293ParhamSoltaniElectrical Engineering, Digital Electronics, IUST, Tehran, IranMohammadJavadJannatiElectrical Engineering, Secure Telecommunications, IUST, Tehran, Iran0000-0001-9457-4715Journal Article20250806Probabilistic dummy operations inject randomized activity into power traces to blur key-dependent leakage, blunting classical side-channel attacks such as CPA and DPA. We introduce a profiling attack that treats traces as sequences of windows and learns to separate key-dependent computation from dummy activity. A lightweight recurrent sequence classifier is trained on traces from an identical device with dummies disabled, producing a model that scores windows for key-bearing work. <br>At attack time, the classifier filters dummy-protected traces and the retained windows feed a standard likelihood or correlation-based-key-ranking stage. The key-recovery advantage arises because filtering removes windows with negligible key-dependent leakage, increasing the effective signal-to-noise ratio for classical distinguishers, while the recurrent architecture’s temporal context enables robust detection despite timing jitter and variable dummy density. On a DES implementation with randomized dummy insertion, our method attains rank-0 with substantially fewer traces than CPA, DPA and a tuned CNN, and remains robust under timing jitter (<span class="mord">±10</span> samples), varying dummy rates (<span class="mord"><em>p</em></span><span class="mrel"> = </span><span class="mord">0.3</span>–<span class="katex-mathml">0.7</span>), and low SNR(<span class="mrel">≤</span><span class="mord">5dB)</span>. We report window-level metrics (<em>AUC, </em>) and key-level success curves (rank vs. traces), with ablations isolating the effects of alignment error and dummy probability. The results demonstrate that probabilistic dummy insertion alone is insufficient against sequence-aware profiling attacks, and that hybrid DL-classical pipelines can outperform both pure classical and pure end-to-end deep learning approaches.https://eej.aut.ac.ir/article_6042_838aac83e00e8c5ca0f839c96d6cb3be.pdf