Shahed UniversityJournal of Communication Engineering2322-40887220181201Radiation Pattern Analysis of Inverted-F Antenna Mounted on the Side Wall of a Long Cylinder11168210.22070/jce.2018.2883.1069ENSeyyed Mohamad JavadRazaviDepartment of Electrical and Electronics Engineering, Malek Ashtar University, P. O. Box 1774-15875, Tehran, Iran.0000-0003-4059-8089DavodBasaeryElectrical and Electronics Engineering Dept., Malek-e-Ashtar University of Technology, Tehran, IranSeyed HoseinMohseni ArmakiElectrical and Electronics Engineering Dept., Malek-e-Ashtar University of Technology, Tehran, IranJournal Article20171013An analytical technique is proposed for estimation of the radiation pattern of inverted-F antenna (IFA) which is mounted on the side wall of a long cylinder. The method can be applied to describe the IFA radiation in a lot of practical cases. It is indicated that this radiation pattern is a combination of radiation patterns of a horizontal and a vertical small radiator, near the cylinder with a certain proportion. Some discussion is presented about this proportion and analytical results are compared with the simulations. Also the proportion is formulated in terms of antenna dimensions using a GA optimization. Finally a typical applicable IFA with smooth radiation pattern is fabricated and its radiation pattern is measured to verify the proposed method. The proposed method can help the designer to estimate the radiation pattern of IFA antenna that mounted on a big cylinder quickly before the simulation.https://jce.shahed.ac.ir/article_682_a17f4b269187226df97291cd5792c88f.pdfShahed UniversityJournal of Communication Engineering2322-40887220181201Incremental adaptive networks implemented by free space optical (FSO) communication122869910.22070/jce.2018.3417.1092ENAmirAminfarDepartment of electrical and computer engineering, Urmia University.0000-0002-4897-7190MehdiChehel AmiraniUrmia universityChangizGhobadiUrmia University0000-0002-2664-1805Journal Article20180508The aim of this paper is to fully analyze the effects of free space optical (FSO) communication links on the estimation performance of the adaptive incremental networks. The FSO links in this paper are described with two turbulence models namely the Log-normal and Gamma-Gamma distributions. In order to investigate the impact of these models we produced the link coefficients using these distributions and assumed that the network is exchanging data between the nodes that are contaminated with these coefficients. Firstly, by the FSO link assumption, we performed the theoretical analysis for the steady-state performance of the adaptive network and driven closed-form relations explaining the link impacts. Secondly, we performed simulation results for Log-normal and Gamma-Gamma link conditions and presented various results for different levels of turbulence. Finally, we compared the theoretical and analytical results showing a close agreement between these two findings. The results are presented by the means of mean square deviation (MSD) and excess mean square error (EMSE) values.https://jce.shahed.ac.ir/article_699_4412b3dad2d89b8015cd0905500755b0.pdfShahed UniversityJournal of Communication Engineering2322-40887220181201A Lightweight Intrusion Detection System Based on Specifications to Improve Security in Wireless Sensor Networks296069210.22070/jce.2018.3539.1098ENMahdiSadeghizadehFaculty of Computer and IT Engineering, Shahrood University of Technology, Shahrood, IranOmid RezaMarouziFaculty of Electrical and Robotic Engineering, Shahrood University of Technology, Shahrood, IranJournal Article20180623Due to the prevalence of Wireless Sensor Networks (WSNs) in the many mission-critical applications such as military areas, security has been considered as one of the essential parameters in Quality of Service (QoS), and Intrusion Detection System (IDS) is considered as a fundamental requirement for security in these networks. This paper presents a lightweight Intrusion Detection System to protect the WSNs against the most important of routing attacks in network layer based on their extracted specifications. The proposed IDS, in contrast to related works that often focuses on a specific attack, covers almost all recognized important routing attacks in WSNs. With the full simulation of the routing attacks and the careful examination of their behavior, we extracted key specifications to identify them in the proposed system. Also, due to local operations provided to detect and significantly reduce communications, the proposed method is a lightweight approach. Another advantage of the proposed method is reducing false alarms rate by applying appropriate thresholds. We considered all performance criteria to evaluate and compare the proposed method. Simulation results show that the proposed system is an effective and lightweight IDS in WSNs due to high detection accuracy, low false alarms rate, and low power consumption.https://jce.shahed.ac.ir/article_692_c0f893b7e4f4b3c99514b4b43904f737.pdfShahed UniversityJournal of Communication Engineering2322-40887220181201A Priority-based Routing Algorithm for Underwater Wireless Sensor Networks (UWSNs)617970410.22070/jce.2018.2975.1071ENAbbas AliRezaeeAssistant Professor, Department of Computer Engineering and Information Technology, Payame Noor University, PO BOX 19395-3697 TehranMohammad HadiZahediAssistant professor at Faculty of Computer Engineering, K.N. Toosi University of Technology Tehran, IranJournal Article20171121Advances in low-power electronics design and wireless communication have enabled the development of low cost, low power micro-sensor nodes. These sensor nodes are capable of sensing, processing and forwarding which have many applications such as underwater networks. In underwater wireless sensor networks (UWSNs) applications, sensors which are placed in underwater environments and predicted enable applications in oceanographic data collection, mine reconnaissance, pollution, assisted navigation, distributed tactical surveillance, and ocean sampling. Each sensor uses acoustic signals as its physical medium for communications. This study focuses on a priority-based routing protocol in underwater wireless sensor networks. This routing method tries to improve the QOS requirements with considering high and low priority traffic classes. Through simulation study using the OPNET simulator, we proved that proposed algorithm achieves high performance as compared to GEDAR, in terms of packet loss, end to end delay of data transmission and energy consumption.https://jce.shahed.ac.ir/article_704_e10f128b5c4df10f1fb6773f3ce9fd19.pdfShahed UniversityJournal of Communication Engineering2322-40887220181201Target Tracking with Unknown Maneuvers Using Adaptive Parameter Estimation in Wireless Sensor Networks506670510.22070/jce.2018.3078.1079ENMortezaSepahvandInformation and Communication Technology FacultyAliNaseriDepartment of Communication and Information Technology, Imam Hossein Comprehensive University, Tehran, IranMeysamRaeesdanaeeDepartment of Communication and Information Technology, Imam Hossein Comprehensive University, Tehran, IranMohammad HosseinKhanzadehDepartment of Communication and Information Technology, Imam Hossein Comprehensive University, Tehran, IranJournal Article20180226Abstract- Tracking a target which is sensed by a collection of randomly deployed, limited-capacity, and short-ranged sensors is a tricky problem and, yet applicable to the empirical world. In this paper, this challenge has been addressed a by introducing a nested algorithm to track a maneuvering target entering the sensor field. In the proposed nested algorithm, different modules are to fulfill different functions, including sensor selection, adaptive maneuver parameter estimation, and target trajectory extraction. To that end, proposed algorithm combines the auxiliary particle filter with the Liu and West filter and applies them for the first time in the wireless sensor network. Its performance is compared to one of the most common approaches for this kind of problem and the results show the superiority of proposed method in terms of the estimation accuracy. The simulation study also involves evaluating the proposed algorithm based on the scalability criterion and the results are promising since the reduction by 40 percent in the number of active sensors leads to, respectively, 18.2 and 14.3 percent increments in the RMSE of position and velocity estimates.https://jce.shahed.ac.ir/article_705_8c32b10539ab244b78f3ec66b23e974f.pdfShahed UniversityJournal of Communication Engineering2322-40887220181201Polarization of Multi-Relay Channels: A Suitable Method for DF and CF Relaying with Orthogonal Receiver617073910.22070/jce.2018.2132.1028ENHassanTavakoliIran, Guilan, Rasht, University of GuilanSaiedPakravanUniversity of GuilanJournal Article20161108Polar codes, that have been recently introduced by Arikan, are one of the first codes that achieved the capacity for vast numerous channels and they also have low complexity in symmetric memoryless channels. Polar codes are constructed based on a phenomenon called channel polarization. This paper discusses relay channel polarization in order to achieve the capacity and show that if inputs of two different relay channels follow the Arikan polarization structure, then they will be categorized as good and bad relay channels. Also, it has been shown that the eencoding and decoding complexity for these codes is , and their error probability is like the Arikan's work. In order to validate our construction of polar codes for relay channels, some numerical examples for this idea have been presented. Also, the efficiency of this construction for decode-and-forward and compress-and-forward relaying strategies have been analyzed by using simulation results for finite block length in relay channels with orthogonal receiver.https://jce.shahed.ac.ir/article_739_2e35366a502aa3ea882cbc8ddc2736bd.pdfShahed UniversityJournal of Communication Engineering2322-40887220181201Performance of Target Detection in Phased-MIMO Radars11174010.22070/jce.2018.3362.1089ENSafiehJebaliDepartment of Communication Engineering, University of Sistan and BaluchestanHengamehKeshavarzCommunication engineering, University of Sistan and BaluchestanJournal Article20180423In this paper, the problem of target detection in phased-MIMO radars is considered and target detection performance of phased-MIMO radars is compared with MIMO and phased-array radars. Phased-MIMO radars combine advantages of the MIMO and phased-array radars. In these radars, the transmit array will be partitioned into a number of subarrays that are allowed to overlap and each subarray transmits a waveform which is orthogonal to the waveform transmitted by other subarrays. In this paper, target detection performance of phased-MIMO radars is analysed with two detectors theoretically and simulation results in two cases. First, it is assumed that the transmitted waveforms are ideally orthogonal and secondly the transmitted waveforms are correlated (not fully coherent or ideally orthogonal). The Generalized likelihood ratio test (GLRT) and the likelihood ratio test (LRT) are used for target detection. The closed-form expressions of the false alarm probability and detection probability in presence of Gaussian noise are obtained. Simulation results validate the theoretical analysis.https://jce.shahed.ac.ir/article_740_784a6c309953a571ea04f0f959c6a998.pdfShahed UniversityJournal of Communication Engineering2322-40887220181201Design and Simulation of an X Band LC VCO122074810.22070/jce.2018.3518.1097ENOmidReyhani-GalangashiFaculty of Electrical, Biomedical and Mechatronics Engineering, Qazvin Branch, Islamic Azad University, Qazvin, IranMahmoodMohammadtaheriSchool of Electrical and Computer Engineering, Faculty of Engineering, University of TehranMohamadDosaranian-MoghadamFaculty of Electrical, Biomedical and Mechatronics Engineering, Qazvin Branch, Islamic Azad University, Qazvin, IranJournal Article20180613In this paper, a systematic method for the circuit parameters design of a monolithic LC Voltage Controlled Oscillator (VCO) is reported. The method is based on the negative resistance generation technique. As a result, a VCO has been designed in 0.18um CMOS technology using a conventional VCO structure to obtain the optimum values for the phase noise and power consumption. The simulation results prove that the proposed approach is very reliable and can be developed further for more complex structures. In this paper, the minimum phase noise of -110.94 dBc/Hz has been obtained at 1 MHz offset frequency at the operating frequency of 10.67 GHz. Furthermore, the designed VCO has the low power consumption of 1.8 mW at the fundamental frequency. In addition, the designed VCO has 1280 MHz of tuning range from 9.39 GHz to 10.67 GHz around the central frequency of 10 GHz. Also, simulation results show that the maximum output power of the signal in the designed VCO is 6.24 dBm.https://jce.shahed.ac.ir/article_748_c6e2bed0362d4e6ec1ee8a925265977d.pdfShahed UniversityJournal of Communication Engineering2322-40887220181201Design of Grounding Vertical Rods Buried in Complex Soils using Radial Basis Functions304075810.22070/jce.2018.3371.1090ENVahidAghajaniMSC student from Arak University, Engineering faculty, Arak, IranS. S.SajjadiMSC student from Arak University, Engineering faculty, Arak, IranSaeed RezaOstadzadehArak universityJournal Article20180426In this paper, using neural networks based on radial basis functions (RBF), a comprehensive closed-form solution for effective length of vertical grounding rod is extracted in such a way that the two effects of ionization and dispersion are simultaneously considered. In creating the model, training data are computed from multi-conductor transmission line (MTL). As a results, firstly in the proposed model, in despite of previous models considering either ionization or dispersion, both effects are included. Secondly, the results are in excellent agreement with the MTL. The achieved results for effective length show that considering both effects simultaneously results in a length which is greater than the one in only-dispersive soil, and less than the one in only-ionized soil. It is well known that this is financially of importance.https://jce.shahed.ac.ir/article_758_da16d476777502ccf2cb2fb5ee0a7e0b.pdfShahed UniversityJournal of Communication Engineering2322-40887220181201Jointly power and bandwidth allocation for a heterogeneous satellite network708076010.22070/jce.2018.3564.1099ENPedramHajipourDepartment of Communication, College of Electrical Engineering,Yadegar-e-Imam Khomeini (RAH)Shahr-e-rey Branch, Islamic Azad University,Tehran,Iran.AliShahzadiFaculty of Electrical and
Computer Engineering , Semnan University,
Semnan, Iran.SaeedGhazi-maghrebiDepartment of
Communication, College of Electrical
Engineering, Yadegar-e-Imam Khomeini
(RAH) Shahr-e-rey Branch, Islamic Azad
University, Tehran, Iran.Journal Article20180702Due to lack of resources such as transmission power and bandwidth in satellite systems, resource allocation problem is a very important challenge. Nowadays, new heterogeneous network includes one or more satellites besides terrestrial infrastructure, so that it is considered that each satellite has multi-beam to increase capacity. This type of structure is suitable for a new generation of communications, which leads to a specific benefit of using the available resource in wireless communication systems. The multi-beam technology is one of the multiple access methods for new satellite systems that are similar to very high throughput satellites systems. Therefore, in this paper, our proposed algorithm is mainly the jointly power and bandwidth allocation of satellite systems to each beam and it is simulated considering the limitation of the total transmission power and bandwidth constraints for any beams. Furthermore, a bandwidth sharing algorithm is provided to dedicate extra bandwidth among beams. Finally, the total capacity of our proposed system model, which is heterogeneous network is obtained based on some parameters such as frequency reuse, modulation rate and total number of users for each beam. This comparison shows that the proposed algorithm allows maintaining the optimal capacity allocation to use a new satellite network.https://jce.shahed.ac.ir/article_760_5b8af0159f2889175ac0ff5836598911.pdf