Journal articles on the topic 'Wireless communication systems – Mathematical models'
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Nalapko, Oleksii, Oleg Sova, Andrii Shyshatskyi, Anatolii Hasan, Vira Velychko, Oleksandr Trotsko, Dmytro Merkotan, Nadiia Protas, Roman Lazuta, and Оleksandr Yakovchuk. "Analysis of mathematical models of mobility of communication systems of special purpose radio communication systems." Technology audit and production reserves 4, no. 2(60) (July 31, 2021): 39–44. http://dx.doi.org/10.15587/2706-5448.2021.237433.
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The object of research is the military radio communication system. One of the problems in improving the effectiveness of military radio communication systems is the correct description of the movement process in them. Efficient routing protocols are only possible if reliable information on network topology for network nodes is available. Thus, with this information, packets can be forwarded correctly between the sender and the recipient. Given that the mobility of individual nodes is insignificant in special wireless networks, nodes in the network show the mobility properties of a group of nodes. This observation is directly related to the very existence of military wireless networks with the ability to organize themselves, that is, to support group cooperation and group activities. In this work the problem of analysis (decomposition) of the mobility models of military radio communication networks with the possibility of self-organization is solved. The classification of mobility patterns, the description of individual mobility models and the analysis of various aspects currently available, as well as those properties lacking in the attempt to simulate the movement of individual nodes, have been carried out. During the research, the analysis of random, semi-deterministic and deterministic models was carried out. The advantages and disadvantages of the above models have been identified. In the course of the research, the authors of the work used the main principles of the theory of mass service, the theory of automation, the theory of complex technical systems, as well as general scientific methods of knowledge, namely analysis and synthesis. The research results will be useful in: ‒ synthesis of mathematical models of node mobility; ‒ evaluation of the effectiveness of the science-based tool for assessing the mobility of nodes; ‒ validation of recommendations to improve the efficiency of mobile radio networks; ‒ analysis of the radio-electronic situation during the conduct of military operations (operations); ‒ creating advanced technologies to improve the efficiency of mobile radio networks.
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Surya, S., Sumeet Gupta, Abolfazl Mehbodniya, Jeidy Panduro-Ramirez, Prabhakara Rao Kapula, Tanweer Alam, and Karthikeyan Kaliyaperumal. "Addressing the Real World Problem of Managing Wireless Communication Systems Using Explainable AI-Based Models through Correlation Analysis." Mathematical Problems in Engineering 2022 (March 23, 2022): 1–6. http://dx.doi.org/10.1155/2022/3390075.
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In a general parlance, wireless communication tends to be investigated based on the available methods that support enhancing the optimized data link, especially the software-based methods. AI is mainly used to create and design efficient communication network systems and variable node locations. The major factors impacting wireless communications in the current context are enhanced channel frequency, efficiency of using the bandwidth, and modulation type. The software-defined ratio enables collecting the information and analyzing the overall signal-related components and processing them in real-time situations. This will support in detecting unnecessary information and identifying latency at each stage of communication. The study is intended to measure the influence of critical factors in enhancing the overall management of wireless communication systems through the application of AI technologies. The researchers used the questionnaire method in order to collect the data from the respondents and enable them to analyze the data using the SPSS data package.
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Li, Yanjun. "Mathematical Modeling Methods and Their Application in the Analysis of Complex Signal Systems." Advances in Mathematical Physics 2022 (October 7, 2022): 1–10. http://dx.doi.org/10.1155/2022/1816814.
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Mathematical models are effective means of answers established by humans to solve real-world problems. Complex wireless communication can establish information interaction between vehicles, in order to reduce the delay time of the coordination control optimization timing scheme in coordination delay time. For smart car driving, a complex signal system, this study first establishes a relevant mathematical model. It is used to compare three mathematical models commonly used today. The results obtained under the same conditions show that the mathematical model is better in dealing with the complex signal system in terms of transmission accuracy in all segments. A number of vehicles in different states of the traffic system are selected, and the relevant data are collected to plot ROC curves using the mathematical model. It can be concluded that the freer and more complex the movement behavior of the vehicle, the greater the load it imposes on the road and the system. The results of the confusion matrix show that the model can effectively reduce the pressure on the road and the signal system. With the starting objective of smooth operation of public transportation, the target values are optimized by layering, and finally, the regional roadway capacity is effectively converged. Then, the mathematical model optimization of complex wireless systems and intelligent transportation networks is quantitatively evaluated. The optimized timing scheme through coordinated control achieves the expected effect in coordinated control of delay time and also reduces the average delay time of all intersections of the road network.
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Sun, Qiushi, Haitao Wu, and Ovanes Petrosian. "Optimal Power Allocation Based on Metaheuristic Algorithms in Wireless Network." Mathematics 10, no. 18 (September 14, 2022): 3336. http://dx.doi.org/10.3390/math10183336.
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An optimal power allocation is a fundamental challenge for massive multiple-input–multiple-output (MIMO) systems because the power allocation should be acclimated to time-varying channels and heavy traffic conditions throughout the communication network. Although massive model-driven algorithms have been employed to solve this issue, most of them require analytically tractable mathematical models and have a high computational complexity. This paper considers the metaheuristic algorithms for the power allocation issue. A series of state-of-the-art stochastic algorithms are compared with the benchmark algorithm on network scales. The simulation results demonstrate the superiority of the proposed algorithms against the conventional benchmark algorithms.
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Bakulin, Mikhail G., Taoufik Ben Camille Ben Rejeb, Vitaly B. Kreyndelin, Denis Y. Pankratov, and Alexey E. Smirnov. "NOMA schemes with symbol level processing." T-Comm 16, no. 5 (2022): 4–14. http://dx.doi.org/10.36724/2072-8735-2022-16-5-4-14.
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Requirements for KPI in 6G networks are significantly higher than in 5G networks. Non-orthogonal multiple access (NOMA) technology has been proposed as a solution to meet the requirements of future communication networks. NOMA technology aims to improve the spectral efficiency of wireless communication systems and support the simultaneous operation of large number of subscribers (especially in mMTC scenarios) and provide flexible resource use. This article discusses the popular symbol-level processing NOMA schemes recently proposed as part of the 3GPP standardization, such as SCMA, PDMA, WSMA, MUSA, and other varieties of NOMA. The main advantages and principles of non-orthogonal access technology are illustrated using the NOMA system with division in power domain (PD-NOMA) for uplink and downlink. Characteristics of various symbol-level processing NOMA schemes, their advantages and disadvantages, as well as problems in the way of their implementation in future wireless networks are analyzed. In addition, this article discusses block diagrams of NOMA systems and mathematical models illustrating the formation of baseband signals in such systems. In conclusion, the noise immunity characteristics of the most popular NOMA schemes with symbol-level processing are given for various loading factors. From the analysis performed, it follows that no NOMA scheme has yet been proposed that is effective in various scenarios of future wireless communication systems and has an acceptable processing complexity in combination with flexible resource allocation for mass connection of subscriber devices.
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Al-Ma’aitah, Mohammed, Aldosary Saad, and Ayed Alwadain. "Modeling of the Schemes for Organizing a Session of Person–System Interactions in the Information System for Critical Use Which Operates in a Wireless Communication Environment." Symmetry 13, no. 3 (February 27, 2021): 391. http://dx.doi.org/10.3390/sym13030391.
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In this article, for the first time, a new mathematical model of the schemes for organizing a session of person–system interactions between the registration center server of the information system for critical use (ISCU) and the terminal of the person-user in a wireless communication environment are presented. In contrast to the existing literature, this article uses the mathematical apparatus of queuing systems to describe the schemes of organizing the stochastic process of a session of person–system interaction in discrete or continuous time, namely, models of the type Geo/Geo/1 with group arrival and ordinary service for the case of discrete representation of time and models of the type M/G/1 for the case of continuous time representation. The use of the mathematical apparatus of queuing systems in the studies made it possible to obtain analytical expressions for comparing formalized schemes for organizing the person–system interaction according to such functional characteristics as the average time of downloading a finite number of data blocks into the terminal of the target person-user (average time that the request spent the server of the information system).
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Zhang, Zhenyu, Anas Chaaban, and Lutz Lampe. "Physical layer security in light-fidelity systems." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 378, no. 2169 (March 2, 2020): 20190193. http://dx.doi.org/10.1098/rsta.2019.0193.
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Light-fidelity (LiFi) is a light-based wireless communication technology which can complement radio-frequency (RF) communication technologies for indoor applications. Although LiFi signals are spatially more contained than RF signals, the broadcasting nature of LiFi also makes it susceptible to eavesdropping. Therefore, it is important to secure the transmitted data against potential eavesdroppers. In this paper, an overview of the recent developments pertaining to LiFi physical layer security (PLS) is provided, and the main differences between LiFi PLS and RF PLS are explained. LiFi achievable secrecy rates and upper bounds are then investigated under practical channel models and transmission schemes. Beamforming and jamming, which received significant research attention recently as a means to achieve PLS in LiFi, are also investigated under indoor illumination constraints. Finally, future research directions of interest in LiFi PLS are identified and discussed. This article is part of the theme issue ‘Optical wireless communication’.
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Korzeniewski, Grzegorz, and Roberto Carrasco Álvarez. "Industrial wireless channel measurements in a 2.4 GHz ISM radio band using a low-cost SDR-based channel sounder." RECIBE, REVISTA ELECTRÓNICA DE COMPUTACIÓN, INFORMÁTICA, BIOMÉDICA Y ELECTRÓNICA 9, no. 1 (June 11, 2020): E1–1—E1–25. http://dx.doi.org/10.32870/recibe.v9i1.150.
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Industrial wireless channel is a challenge for the design of communication systems, due to non-Line-of-Sight transmission, caused by the presence of many highly reflective obstacles, and machines in operation, which are a source of the increased noise level. The main effect, which must be analyzed, is multipath propagation. In this article, a low-cost sounding system is proposed, based on Software Defined Radio (SDR) equipment, with the intention of making sounding devices more accessible to a larger group of researchers. Likewise, the mathematical foundations and the software/hardware implementation of the wireless channel sounding system are presented, and the solutions to mitigate the synchronization issues and SDR limitations are also introduced. The performance of the proposed sounder is validated through a measurement campaign in an industrial workshop, considering the 2.4 GHz Industrial, Scientific, Medical (ISM) band. Channel sounding measurements corroborate the accuracy of the results, which converge with the channel mathematical models proposed for several industrial environments and reported in the state-of-the-art literature. In this sense, the proposed channel sounder can be used to investigate the wireless propagation environments.
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الهذيلي, محمد احمد احمد, محمد محسن الشدادي, and عبدالباسط محمد البشة. "Analytical Study of Path Loss in Radio Wave Propagation Models of the GSM Cellular Communications Networks in the City of Sana'a." Journal of Science and Technology 23, no. 1 (October 28, 2018): 41–56. http://dx.doi.org/10.20428/jst.v23i1.1399.
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The rapid growth of wireless communication technologies has increased the importance of a proper network planning. Before the actual installation of the network and to ensure that the network is adequately covered, network designers rely heavily on wave propagation models, which are a set of mathematical expressions, and graphs derived from comprehensive field measurements and it is used to represent radio wave properties of a particular environment. The research aims to find a mathematical model to predict the propagation path loss of radio waves in Sana'a city for the appropriate planning of cellular communication systems. In this sense, the researcher applied a practical study to the city of Sana'a by taking three cells (base station) in three different regions (urban and suburban areas and the open area). The research focuses on three stages (the stage of measurements, the stage of analysis and the stage of analysis and comparison). In the results, we obtained three values for path loss constants a and c for the three regions, through which we obtain the logarithmic curves, which in turn has been transformed into mathematical models to be used as a reference for radio planning engineers in the city of Sana'a, the capital of the Republic of Yemen.
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Joshi, Ashish, and Amar Kumar Mohapatra. "Security Analysis of Wireless Authentication Protocols." International Journal of Sensors, Wireless Communications and Control 9, no. 2 (October 25, 2019): 247–52. http://dx.doi.org/10.2174/2210327908666180806112157.
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Background & Objective: Cryptographic protocols had been evident method for ensuring con dentiality, Integrity and authentication in various digital communication systems. However the validation and analysis of such cryptographic protocols was limited to usage of formal mathematical models until few years back. Methods: In this paper, various popular cryptographic protocols have been studied. Some of these protocols (PAP, CHAP, and EAP) achieve security goals in peer to peer communication while others (RADIUS, DIAMETER and Kerberos) can work in multiparty environment. These protocols were validated and analysed over two popular security validation and analysis tools AVISPA and Scyther. The protocols were written according to their documentation using the HLPSL and SPDL for analysis over AVISPA and Scyther respectively. The results of these tools were analysed to nd the possible attack an each protocol. Afterwards The execution time analysis of the protocols were done by repeating the experiment for multiple iterations over the command line versions of these tools.As the literature review suggested, this research also validates that using password based protocols (PAP) is faster in terms of execution time as compared to other methods, Usage of nonces tackles the replay attack and DIAMETER is secure than RADIUS. Results and Conclusion: The results also showed us that DIAMETER is faster than RADIUS. Though Kerberos protocol was found to safe, the results tell us that it is compromisable under particular circumstances.
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Mishra, Rohit, Yiqi Zhang, Fenglong Ma, and Anlong Li. "The Prediction of Collisions in Connected Vehicle Systems with A Long Short-Term Memory Model." Proceedings of the Human Factors and Ergonomics Society Annual Meeting 64, no. 1 (December 2020): 775–79. http://dx.doi.org/10.1177/1071181320641178.
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The advances in connected vehicle systems (CVS) allow vehicles to communicate with each other and with infrastructures via wireless communication networks. This technology enables vehicles to detect potential hazards on the road, generate warnings, and assist the driver in taking preventive actions. To date, few mathematical models have been developed to predict the collision rates in connected vehicle systems. In this work, a Long Short-Term Memory model (LSTM) using time-series data of human drivers was developed to predict the collision rates in CVS by quantifying warning parameters and hazard scenario features. The model was validated with the driving performance data before and after warnings from thirty-two drivers in a behavioral experiment. The results indicated the LSTM model showed a prediction accuracy of 74% higher than SVM and logistic regression models. The LSTM model showed the potential to help optimize the warning algorithm in the connected vehicle systems to improve driver safety.
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Et. al., Rohit Chawla,. "Study of Security Threats and Challenges in Internet of Things Systems." Turkish Journal of Computer and Mathematics Education (TURCOMAT) 12, no. 2 (April 11, 2021): 1154–66. http://dx.doi.org/10.17762/turcomat.v12i2.1137.
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The interpretability and secured communication are major challenge in internet of things. The embedding of wireless device has low energy and bandwidth. The low energy and bandwidth cannot effort computational overhead and compromised with security threats. Primary the conventional cryptography algorithm is applied for generation and sharing of key for mode of communication. The conventional cryptography algorithms have several bottleneck issues related to generation of key and distribution of key. The NIST models provides the secured communication channel in the environments of mobility. Lack of integrity, confidentiality and authorization process of data transmitted over the network of internet of things used the concept of key generation and allocation. The process of key generation and authentication provides the authorization and authentication of data over the internet of things. In this paper present the review of security threats of internet of things.
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Pospelov, Boris, Olena Petukhova, Ruslan Meleshchenko, Stella Gornostal, and Sergey Shcherbak. "Development of communication models of wireless environment in emergency situations." Eastern-European Journal of Enterprise Technologies 2, no. 9 (92) (March 27, 2018): 40–47. http://dx.doi.org/10.15587/1729-4061.2018.127023.
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Knyazev, Volodymyr, Vladimir Kravchenko, Bogdan Lazurenko, Oleksandr Serkov, Karyna Trubchaninova, and Nataliia Panchenko. "Development of methods and models to improve the noise immunity of wireless communication channels." Eastern-European Journal of Enterprise Technologies 1, no. 5(115) (February 25, 2022): 35–42. http://dx.doi.org/10.15587/1729-4061.2022.253458.
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It has been shown that existing methods and models for improving the noise immunity of communication channels are not capable of meeting requirements for the quality of information in mobile infocommunication systems. In addition, the compromised quality of information fails to protect it and provide the speed of information transmission and density of access channels. It has been proven that reducing the level of electromagnetic radiation is the main method of ensuring noise immunity in wireless mobile communication systems of infocommunication systems. Therefore, one way to ensure the stable interference-free operation is to reduce the level of the information signal at the receiver input to the noise level when the signal/noise ratio is equal to one. This paper reports the results of studying methods and models with correlation reception of ultra-wideband signals. It is proved that according to the level of potential noise immunity, the best indicators are shown by the model of encoding an ultra-wideband information signal by phase manipulation, followed by the coding model with opposite chips, and the code-time manipulation model. It is shown that with a large base of the signal B>300 when the intensity of the received signals is below the level of interference, reliable transmission of information is carried out with a probability of error of less than 10-6. This proves that the use of ultra-wide signal technology allows for wireless hidden transmission of information with low radiation power and a low probability of error. Thus, at a speed of 12 Mb/s, it is possible to chain the transmission of information with a probability of error less than 10-6 if there is a large signal base used, B =500‒1000.
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Duong, Huu Ai, Van Loi Nguyen, and Khanh Ty Luong. "Misalignment fading effects on the ACC performance of relay-assisted MIMO/FSO systems over atmospheric turbulence channels." International Journal of Electrical and Computer Engineering (IJECE) 12, no. 1 (February 1, 2022): 966. http://dx.doi.org/10.11591/ijece.v12i1.pp966-973.
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<span>The continuous development of internet of things (IoT) technology enables many devices to be interconnected through the external environment. Meanwhile, 5G technology provides an enhanced quality of services with high data transmission rates, requiring IoT implementation in the 5G architecture. Free-space optical communication (FSO) is considered a promising technique that can provide high-speed communication links, so FSO is an optimal choice for wireless networks to fulfill the full potential of 5G technology, providing speeds of 100 Gb/s or more. By implementing 5G features in IoT, IoT coverage and performance will be enhanced by using FSO models. Therefore, the paper proposed and investigated the multiple-input and multiple-output/free-space optical communication (MIMO/FSO) model using subcarrier quadrature amplitude modulation (SC-QAM) and relay stations over atmospheric turbulence channels by log-normal and gamma-gamma distribution under different turbulence conditions. The performance is examined based on the average channel capacity (ACC), which is expressed in terms of average spectral efficiency (ASE) parameters while changing the different parameters of the model. The mathematical formulas of ACC for atmospheric turbulence cases are calculated and discussed the influence of turbulence strength, the different number of relay stations, misalignment effects, and different MIMO configurations.</span>
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Krishna, Ram, Agbotiname Lucky Imoize, Rajveer Singh Yaduvanshi, Harendra Singh, Arun Kumar Rana, and Subhendu Kumar Pani. "Analysis of Multi-Stacked Dielectric Resonator Antenna with Its Equivalent R-L-C Circuit Modeling for Wireless Communication Systems." Mathematical and Computational Applications 28, no. 1 (December 29, 2022): 4. http://dx.doi.org/10.3390/mca28010004.
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The dielectric resonator antenna (DRA) can be modeled as a series and parallel combination of electrical networks consisting of a resistor (R), inductor (L), and capacitor (C) to address peculiar challenges in antennas suitable for application in emerging wireless communication systems for higher frequency range. In this paper, a multi-stacked DRA has been proposed. The performance and characteristic features of the DRA have been analyzed by deriving the mathematical formulations for dynamic impedance, input impedance, admittance, bandwidth, and quality factor for fundamental and high-order resonant modes. Specifically, the performance of the projected multi-stacked DRA was analyzed in MATLAB and a high-frequency structure simulator (HFSS). Generally, results indicate that variation in the permittivity of substrates, such as high and low, can potentially increase and decrease the quality factor, respectively. In particular, the impedance, radiation fields and power flow have been demonstrated using the proposed multi-stacked electrical network of R, L, and C components coupled with a suitable transformer. Overall, the proposed multi-stacked DRA network shows an improved quality factor and selectivity, and bandwidth is reduced reasonably. The multi-stacked DRA network would find useful applications in radio frequency wireless communication systems. Additionally, for enhancing the impedance, BW of DRA a multi-stacked DRA is proposed by the use of ground-plane techniques with slots, dual-segment, and stacked DRA. The performance of multi-stacked DRA is improved by a factor of 10% as compared to existing models in terms of better flexibility, moderate gain, compact size, bandwidth, quality factor, resonant frequency, frequency impedance at the resonance frequency, and the radiation pattern with Terahertz frequency range.
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Zadobrischi, Eduard, Lucian-Mihai Cosovanu, and Mihai Dimian. "Traffic Flow Density Model and Dynamic Traffic Congestion Model Simulation Based on Practice Case with Vehicle Network and System Traffic Intelligent Communication." Symmetry 12, no. 7 (July 15, 2020): 1172. http://dx.doi.org/10.3390/sym12071172.
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The massive increase in the number of vehicles has set a precedent in terms of congestion, being one of the important factors affecting the flow of traffic, but there are also effects on the world economy. The studies carried out so far try to highlight solutions that will streamline the traffic, as society revolves around transportation and its symmetry. Current research highlights that the increased density of vehicles could be remedied by dedicated short-range communications (DSRC) systems through communications of the type vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I) or vehicle-to-everything (V2X). We can say that wireless communication technologies have the potential to significantly change the efficiency and road safety, thus improving the efficiency of transport systems. An important factor is to comply with the requirements imposed on the use of vehicle safety and transport applications. Therefore, this paper focuses on several simulations on the basis of symmetry models, implemented in practical cases in order to streamline vehicle density and reduce traffic congestion. The scenarios aim at both the communication of the vehicles with each other and their prioritization by the infrastructure, so we can have a report on the efficiency of the proposed models.
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Dalef, Huda Hatam, Faieza Abdul Aziz, Wan Zuha Wan Hasan, and Mohd Khairol Anuar Mohd Ariffin. "Development of Wireless Controlling and Monitoring System for Robotic Hand Using Zigbee Protocol." Journal of Computational and Theoretical Nanoscience 15, no. 2 (February 1, 2018): 656–62. http://dx.doi.org/10.1166/jctn.2018.7140.
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Nowadays, the robotic arm is fast becoming the most popular robotic form used in the industry among others. Therefore, the issues regarding remote monitoring and controlling system are very important, which measures different environmental parameters at a distance away from the room and sets various condition for a desired environment through a wireless communication system operated from a central room. Thus, it is crucial to create a programming system which can control the movement of each part of the industrial robot in order to ensure it functions properly. EDARM ED-7100 is one of the simplest models of the robotic arm, which has a manual controller to control the movement of the robotic arm. In order to improve this control system, a new controller system was redesigned in this work by using Zigbee. It is a communication protocol for safety and economic data communication in an industrial field, where the wired communication is either expensive or difficult under physical and experimental conditions, such as the worker cannot recognize the error through the manufacturing process. Hence, this paper introduced a system that used microcontroller (AT89S52) with wireless devices (Zigbee) and sensors to control the robotic hand (EDARM ED-7100) and to monitor the information regarding the robot's parameter using WiFi technology. A mathematical model was derived through an empirical method to specify the robot's configuration changes. In this work, the ability of controlling system had increased, as well as hardware, while the necessities of other similar equipment for data communication were minimized. In addition, it presents the comparison of two controlling systems: using the Zigbee and without using it. Based from the experiment it can be safely concluded that the robotic arm's movement had followed a linear function.
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Alsulami, Osama Zwaid, Amal A. Alahmadi, Sarah O. M. Saeed, Sanaa Hamid Mohamed, T. E. H. El-Gorashi, Mohammed T. Alresheedi, and Jaafar M. H. Elmirghani. "Optimum resource allocation in optical wireless systems with energy-efficient fog and cloud architectures." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 378, no. 2169 (March 2, 2020): 20190188. http://dx.doi.org/10.1098/rsta.2019.0188.
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Optical wireless communication (OWC) is a promising technology that can provide high data rates while supporting multiple users. The optical wireless (OW) physical layer has been researched extensively, however, less work was devoted to multiple access and how the OW front end is connected to the network. In this paper, an OWC system which employs a wavelength division multiple access (WDMA) scheme is studied, for the purpose of supporting multiple users. In addition, a cloud/fog architecture is proposed for the first time for OWC to provide processing capabilities. The cloud/fog-integrated architecture uses visible indoor light to create high data rate connections with potential mobile nodes. These OW nodes are further clustered and used as fog mini servers to provide processing services through the OW channel for other users. Additional fog-processing units are located in the room, the building, the campus and at the metro level. Further processing capabilities are provided by remote cloud sites. Two mixed-integer linear programming (MILP) models were proposed to numerically study networking and processing in OW systems. The first MILP model was developed and used to optimize resource allocation in the indoor OWC systems, in particular, the allocation of access points (APs) and wavelengths to users, while the second MILP model was developed to optimize the placement of processing tasks in the different fog and cloud nodes available. The optimization of tasks placement in the cloud/fog-integrated architecture was analysed using the MILP models. Multiple scenarios were considered where the mobile node locations were varied in the room and the amount of processing and data rate requested by each OW node was varied. The results help to identify the optimum colour and AP to use for communication for a given mobile node location and OWC system configuration, the optimum location to place processing and the impact of the network architecture. This article is part of the theme issue ‘Optical wireless communication’.
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Piltyay, Stepan, Andrew Bulashenko, Hanna Kushnir, and Oleksandr Bulashenko. "Information Resources Economy in Satellite Systems based on New Microwave Polarizers with Tunable Posts." Path of Science 6, no. 11 (November 30, 2020): 5001–10. http://dx.doi.org/10.22178/pos.64-6.
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One of the fundamental problems of modern digital telecommunications is the economy of digital information and frequency resources, which are highly limited. The introduction of novel telecommunication systems and 5G networks requires searching for principal solutions for the economy and reusing the frequency spectrum. Therefore, modern wireless mobile, terrestrial, and satellite systems use various new technologies to increase communication channels' information capacity for the economy of limited frequency resources. One of the most effective ways to reuse the information system's operating frequency band is to apply antennas with polarisation signal processing. Such systems provide the possibility to transmit and to receive simultaneously signals with different types of polarisation. Consequently, the application of electromagnetic waves with two orthogonal polarisations improves wireless systems' information characteristics for various purposes. This allows doubling the information capacity of mobile, terrestrial, and satellite communication channels. Also, polarisation processing is carried out in meteorological and radar systems to receive, transmit, and process information. The essential elements of such systems are microwave polarisers and orthomode transducers. The electromagnetic characteristics of these devices affect the aspects of the whole system significantly. Main electromagnetic factors include phase, matching, and polarisation parameters. The article presents the development of a compact tunable polarizer based on a square waveguide with three posts. The developed polariser operates in the X-band from 8.0 GHz to 8.5 GHz. Created a mathematical model of the polariser is based on the scattering and transmission matrices. To verify the developed theoretical model's correctness, the calculation of all characteristics was also performed numerically using the finite integration technique. The developed compact polariser based on a square waveguide with three posts allows tuning it's matching and polarisation characteristics by changing all posts' heights. The developed polariser's main advantages are small dimensions, tuning options, and aspects of polarisation transformation.
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Isaac Kuma Yeboah, Richard Brace, Kwabena Agyapong-Kondua, Matthew Asiedu, and Henrritta Kuma Yeboah. "Fabrication and optimization of bi-quad antenna and energy-efficient balanced RF power amplifier for 5G-LTE multi-carrier applications." ITU Journal on Future and Evolving Technologies 3, no. 3 (December 15, 2022): 874–85. http://dx.doi.org/10.52953/wcqw1171.
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Wireless technology is presently one of the most actively researched fields of digital communication systems. Wireless communication technologies are insufficient without an understanding of antenna design and operation. A wide range of radio frequency equipment, including microwave antennas, microwave ovens, cordless telephones, and medical devices, utilize the 2.4 GHz band. In this article, a parabolic mesh dish was used to build and improve a bi-quad antenna with a central working frequency of 2.445 GHz. The bi-quad antenna was put in a parabolic mesh dish to optimize wave propagation. The findings show that the antenna obtained a signal strength range of 70% to 80%, increasing the directivity of WLAN coverage. The bi-quad antenna feed was placed in the center of a mesh dish, which assists in focusing radio waves onto the antenna. The bi-quad antenna outperformed the omnidirectional antenna, which had a signal strength of 56%. The results of each antenna test were separately simulated in MATLAB. The combined impact of bi-quad and parabolic was then duplicated using mathematical models, resulting in a unique waveform propagation pattern known as para-quad, which improved performance. A balanced RF power amplifier was conceived and built in this study. A 2.620 - 2.690GHz frequency range on a large signal Si-LDMOS transistor model achieves 53% PAE, 41dBm power output, and 14 dB gain at the P1dB saturation point.
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Gripeos, Panagiotis J., Hector E. Nistazakis, Andreas D. Tsigopoulos, Vasilis Christofilakis, and Evgenia Roditi. "Time and Spatial Jitter Influence on the Performance of FSO Links with DF Relays and OC Diversity Over Turbulence Channels." Photonics 8, no. 8 (August 7, 2021): 318. http://dx.doi.org/10.3390/photonics8080318.
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FSO communication is a viral technology among optical wireless communications, gathering the interest of both researchers and manufacturers. This is because of the many advantages associated with FSO communication, including high data rates, reliability, safety, and economy. However, there are several unavoidable drawbacks that shadow the performance of FSO systems. For example, atmospheric turbulence is a well-known problem related to the weather conditions of the channel, which causes the scintillation effect. Also, spatial jitter due to pointing errors is a critical factor of the link’s performance, caused by occasional misalignments between the transmitter and the receiver. Moreover, time jitter is another limiting agent that deteriorates the total throughput, inducing bit stream misdetections, caused by the arrival of out-of-sync pulses. All three effects have been exhaustively studied and many statistical models and interesting solutions have been proposed in the literature to estimate their magnitude and compensate for their impact. In this work, the turbulence effect was treated by Málaga distribution, the spatial jitter effect was regulated by the non-zero boresight model, and the time jitter effect was modeled by the generalized Gaussian distribution. Various modulation schemes were studied, along with DF multi-hop and optimal combining diversity techniques at the receiver’s end. New, accurate mathematical expressions of average BER performance have been obtained, and valuable conclusions were drawn thanks to the presented numerical results.
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Morocho-Yaguana, Marco, Patricia Ludeña-González, Francisco Sandoval, Betty Poma-Vélez, and Alexandra Erreyes-Dota. "An Optimized Propagation Model based on Measurement Data for Indoor Environments." Journal of Telecommunications and Information Technology 2 (June 29, 2018): 69–75. http://dx.doi.org/10.26636/jtit.2018.117217.
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Propagation is an essential factor ensuring good coverage of wireless communications systems. Propagation models are used to predict losses in the path between transmitter and receiver nodes. They are usually defined for general conditions. Therefore, their results are not always adapted to the behavior of real signals in a specific environment. The main goal of this work is to propose a new model adjusting the loss coefficients based on empirical data, which can be applied in an indoor university campus environment. The Oneslope, Log-distance and ITU models are described to provide a mathematical base. An extensive measurement campaign is performed based on a strict methodology considering different cases in typical indoor scenarios. New loss parameter values are defined to adjust the mathematical model to the behavior of real signals in the campus environment. The experimental results show that the model proposed offers an attenuation average error of 2.5% with respect to the losses measured. In addition, comparison of the proposed model with existing solutions shows that it decreases the average error significantly for all scenarios under evaluation.
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Puspita, Fitri Maya, Bella Juwita Rezky, Arden Naser Yustian Simarmata, Evi Yuliza, and Yusuf Hartono. "Improved incentive pricing-based quasi-linear utility function of wireless networks." Indonesian Journal of Electrical Engineering and Computer Science 22, no. 3 (June 1, 2021): 1467. http://dx.doi.org/10.11591/ijeecs.v22.i3.pp1467-1475.
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The model of the incentive pricing scheme-based quasi-linear utility function in wireless network was designed. Previous research seldom focusses on user’s satisfaction while using network. Therefore, the model is then attempted to be set up that is derived from the modification of bundling and models of reverse charging and maintain the quality of service to users by utilizing quasi-linear utility function. The pricing schemes then are applied to local data server traffic. The model used is known as mathematical programming problem that can be solved by LINGO 13.0 program as optimization tool to get the optimal solution. The optimal results show that the improved incentive pricing can achieve better solution compared to original reverse charging where the models will be obtained in flat fee, usage-based, and two-part tariff strategies for homogeneous consumers.
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Yusof, Azita Laily, Hafizi Halim, Norsuzila Ya'acob, and Nur Haidah Mohd Hanapiah. "Performance Analysis of Propagation in VHF Military Tactical Communication System." Baghdad Science Journal 18, no. 4(Suppl.) (December 20, 2021): 1378. http://dx.doi.org/10.21123/bsj.2021.18.4(suppl.).1378.
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The main challenge of military tactical communication systems is the accessibility of relevant information on the particular operating environment required for the determination of the waveform's ideal use. The existing propagation model focuses mainly on broadcasting and commercial wireless communication with a highs transceiver antenna that is not suitable for numerous military tactical communication systems. This paper presents a study of the path loss model related to radio propagation profile within the suburban in Kuala Lumpur. The experimental path loss modeling for VHF propagation was collected from various suburban settings for the 30-88 MHz frequency range. This experiment was highly affected by ecological factors and existing wave propagation effects such as reflection, diffraction, scattering, and Doppler effect. Radio propagation performance is evaluated by collecting received power at the allocated substation and comparing it against existing propagation models. The existing propagation model also will be tuned close to the measurement value by identifying the best path loss exponent to perform a suitable model for a suburban area. Theoretical assessments and analysis of the initial measurement stage for radio propagation show the extensive contribution of radio field from potential obstacles at lower VHF frequencies for both short and medium ranges around there. The explanation indicates the standard radio propagation prediction models that are generally reasonable for the suburban area. From the general error analysis, it is seen that, the performance of the LDPL with adjusting path loss exponent is the suitable model since it has least value of error metrics.
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Ko, H. S., and S. Y. Nof. "Editorial – Special Issue on Collaboration Support Systems (CSS)." International Journal of Computers Communications & Control 5, no. 1 (March 1, 2010): 6. http://dx.doi.org/10.15837/ijccc.2015.1.2460.
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<p>Recent and emerging advances in computer and information science and technology have realized a powerful computing and communication environment. It enables effective interactions and collaboration among groups of people and systems (and systems-of-systems) beyond traditional restrictions of time and space. The evolution in hardware (e.g., pervasive computing devices, wireless sensor networks, nano-electronics) and software (e.g., multi-agent systems, workflow and information integration, interaction models and protocols) technology, and their flexible teaming have further enabled diverse forms of collaboration approaches. It has been observed during the last few decades that numerous collaboration methodologies, tools and applications in various domains have emerged to provide better quality services, helping to solve domain-specific, highly complex problems. The development of collaboration tools and methodologies has increased the domain knowledge that can be discovered and shared by individuals, and the level and intensity of interactions and collaboration that can dramatically decrease problem complexity and increase solution quality. At the same time, inefficient interactions, task and information overloads, and ineffective collaboration are prevalent.</p>
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Bhatt, Dhruvi S., Shaival H. Nagarsheth, and Shambhu N. Sharma. "On the Theory of a Nonlinear Dynamic Circuit Filtering." Fluctuation and Noise Letters 19, no. 03 (March 5, 2020): 2050022. http://dx.doi.org/10.1142/s0219477520500224.
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Stochastic Differential Equations (SDEs) describe physical systems to account for random forcing terms in the evolution of the state trajectory. The noisy sampling mixer, a component of digital wireless communications, can be regarded as a potential case from the dynamical systems’ viewpoint. The universality of the noisy sampling mixer is attributed to the fact that it adopts the structure of a nonlinear SDE and its linearized version becomes a time-varying bilinear SDE. This paper develops a mathematical theory for the nonlinear noisy sampling mixer from the filtering viewpoint. Since the filtering of stochastic systems hinges on the structure of dynamical systems and observation equation set up, we consider three ‘filtering models’. The first model, accounts for a nonlinear SDE coupled with a nonlinear observation equation. In the second model, we consider a bilinear SDE with a linear observation equation to achieve the nonlinear sampling filtering. Note that the bilinear SDE coupled with the linear observation is a consequence of the Carleman linearization to the nonlinear SDE and the nonlinear observation equation. In the third model, we consider a Stratonovich SDE coupled with a nonlinear observation equation. The filtering equation of this paper can be further utilized to guide the design process of the noisy sampling mixer.
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Zhu, Yanli, Xiaoping Yang, Yi Hong, Youfang Leng, and Chuanwen Luo. "Efficient Energy Utilization with Device Placement and Scheduling in the Internet of Things." Wireless Communications and Mobile Computing 2021 (September 14, 2021): 1–16. http://dx.doi.org/10.1155/2021/5921181.
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The low-power wide-area network (LPWAN) technologies, such as LoRa, Sigfox, and NB-IoT, bring new renovation to the wireless communication between end devices in the Internet of things (IoT), which can provide larger coverage and support a large number of IoT devices to connect to the Internet with few gateways. Based on these technologies, we can directly deploy IoT devices on the candidate locations to cover targets or the detection area without considering multihop data transmission to the base station like the traditional wireless sensor networks. In this paper, we investigate the problems of the minimum energy consumption of IoT devices for target coverage through placement and scheduling (MTPS) and minimum energy consumption of IoT devices for area coverage through placement and scheduling (MAPS). In the problems, we consider both the placement and scheduling of IoT devices to monitor all targets (or the whole detection area) such that all targets (or the whole area) are (or is) continuously observed for a certain period of time. The objectives of the problems are to minimize the total energy consumption of the IoT devices. We first, respectively, propose the mathematical models for the MTPS and MAPS problems and prove that they are NP-hard. Then, we study two subproblems of the MTPS problem, minimum location coverage (MLC), and minimum energy consumption scheduling deployment (MESD) and propose an approximation algorithm for each of them. Based on these two subproblems, we propose an approximation algorithm for the MTPS problem. After that, we investigate the minimum location area coverage (MLAC) problem and propose an algorithm for it. Based on the MLAC and MESD problems, we propose an approximation algorithm to solve the MAPS problem. Finally, extensive simulation results are given to further verify the performance of the proposed algorithms.
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Ding, Qianao, Rongbo Zhu, Hao Liu, and Maode Ma. "An Overview of Machine Learning-Based Energy-Efficient Routing Algorithms in Wireless Sensor Networks." Electronics 10, no. 13 (June 25, 2021): 1539. http://dx.doi.org/10.3390/electronics10131539.
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Machine learning (ML) technology has shown its unique advantages in many fields and has excellent performance in many applications, such as image recognition, speech recognition, recommendation systems, and natural language processing. Recently, the applicability of ML in wireless sensor networks (WSNs) has attracted much attention. As resources are limited in WSNs, identifying how to improve resource utilization and achieve power-efficient load balancing is becoming a critical issue in WSNs. Traditional green routing algorithms aim to achieve this by reducing energy consumption and prolonging network lifetime through optimized routing schemes in WSNs. However, there are usually problems such as poor flexibility, a single consideration factor, and a reliance on accurate mathematical models. ML techniques can quickly adapt to environmental changes and integrate multiple factors for routing decisions, which provides new ideas for intelligent energy-efficient routing algorithms in WSNs. In this paper, we survey and propose a theoretical hypothetic model formulation of ML as an effective method for creating a power-efficient green routing model that can overcome the limitations of traditional green routing methods. In addition, the study also provides an overview of past, present, and future progress in green routing schemes in WSNs. The contents of this paper will appeal to a wide range of audiences interested in ML-based WSNs.
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Madbouly, Magda M., Yasser F. Mokhtar, and Saad M. Darwish. "Quantum Game Application to Recovery Problem in Mobile Database." Symmetry 13, no. 11 (October 20, 2021): 1984. http://dx.doi.org/10.3390/sym13111984.
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Mobile Computing (MC) is a relatively new concept in the world of distributed computing that is rapidly gaining traction. Due to the dynamic nature of mobility and the limited bandwidth available on wireless networks, this new computing environment for mobile devices presents significant challenges in terms of fault-tolerant system development. As a consequence, traditional fault-tolerance techniques are inherently inapplicable to these systems. External circumstances often expose mobile systems to failures in communication or data storage. In this article, a quantum game theory-based recovery model is proposed in the case of a mobile host’s failure. Several of the state-of-the-art recovery protocols are selected and analyzed in order to identify the most important variables influencing the recovery mechanism, such as the number of processes, the time needed to send messages, and the number of messages logged-in time. Quantum game theory is then adapted to select the optimal recovery method for the given environment variables using the proposed utility matrix of three players. Game theory is the study of mathematical models of situations in which intelligent rational decision-makers face conflicting interests (alternative recovery procedures). The purpose of this study is to present an adaptive algorithm based on quantum game theory for selecting the most efficient context-aware computing recovery procedure. The transition from a classical to a quantum domain is accomplished in the proposed model by treating strategies as a Hilbert space rather than a discrete set and then allowing for the existence of linear superpositions between classical strategies; this naturally increases the number of possible strategic choices available to each player from a numerable to a continuous set. Numerical data are provided to demonstrate feasibility.
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Rofiq, Muhammad, and Bambang Tri Wahjo Utomo. "IMPLEMENTASI ALGORITMA ELGAMAL DALAM SISTEM LOCK BRANKAS BERBASIS MIKROKONTROLER ATMEGA16 DAN SMARTPHONE ANDROID." Jurnal Ilmiah Informatika 1, no. 1 (June 9, 2016): 7–16. http://dx.doi.org/10.35316/jimi.v1i1.437.
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Most of Safes lock system is still using conventional methods nowadays. The conventional method leads to the safes’ burglary. Some of the causes are the safes’ code that can be tracked easily and the key can be duplicated. Previous research on safes’ security has ever been done. The weakness of the study is there is no security system using cryptographic algorithms for data security. The development of a safes security system by implementing ElGamal algorithms is done by following the engineering approach with the stages of methods analysis and design system, implementation and testing of the analysis and the discussion of the overall system. In the analysis and design of mathematical models using ElGamal algorithms, uses fast powering theorems and applications design uses Object OrientedProgramming. In the analysis of hardware refers to the datasheet and calculation of the value of electrical characteristics of the circuit. In the safes lock system, the outcome of the research is a safes prototype which is equipped with enhancements that include a series of processing algorithms, the data viewer, a wireless data transfer device, the Android smartphone as a system of user authorization. For the lock safes systems is using a locked solenoid. The control system is done by a lock safes android smartphone via Bluetooth communication. The test results also indicate the system will open the safes if the code and the public key is entered correctly, and the system will not open if one of the codes or the public-keys are wrong or both are wrong.
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Aziz, Saddam, Muhammad Talib Faiz, Adegoke Muideen Adeniyi, Ka-Hong Loo, Kazi Nazmul Hasan, Linli Xu, and Muhammad Irshad. "Anomaly Detection in the Internet of Vehicular Networks Using Explainable Neural Networks (xNN)." Mathematics 10, no. 8 (April 11, 2022): 1267. http://dx.doi.org/10.3390/math10081267.
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It is increasingly difficult to identify complex cyberattacks in a wide range of industries, such as the Internet of Vehicles (IoV). The IoV is a network of vehicles that consists of sensors, actuators, network layers, and communication systems between vehicles. Communication plays an important role as an essential part of the IoV. Vehicles in a network share and deliver information based on several protocols. Due to wireless communication between vehicles, the whole network can be sensitive towards cyber-attacks.In these attacks, sensitive information can be shared with a malicious network or a bogus user, resulting in malicious attacks on the IoV. For the last few years, detecting attacks in the IoV has been a challenging task. It is becoming increasingly difficult for traditional Intrusion Detection Systems (IDS) to detect these newer, more sophisticated attacks, which employ unusual patterns. Attackers disguise themselves as typical users to evade detection. These problems can be solved using deep learning. Many machine-learning and deep-learning (DL) models have been implemented to detect malicious attacks; however, feature selection remains a core issue. Through the use of training empirical data, DL independently defines intrusion features. We built a DL-based intrusion model that focuses on Denial of Service (DoS) assaults in particular. We used K-Means clustering for feature scoring and ranking. After extracting the best features for anomaly detection, we applied a novel model, i.e., an Explainable Neural Network (xNN), to classify attacks in the CICIDS2019 dataset and UNSW-NB15 dataset separately. The model performed well regarding the precision, recall, F1 score, and accuracy. Comparatively, it can be seen that our proposed model xNN performed well after the feature-scoring technique. In dataset 1 (UNSW-NB15), xNN performed well, with the highest accuracy of 99.7%, while CNN scored 87%, LSTM scored 90%, and the Deep Neural Network (DNN) scored 92%. xNN achieved the highest accuracy of 99.3% while classifying attacks in the second dataset (CICIDS2019); the Convolutional Neural Network (CNN) achieved 87%, Long Short-Term Memory (LSTM) achieved 89%, and the DNN achieved 82%. The suggested solution outperformed the existing systems in terms of the detection and classification accuracy.
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Gu, Taochen, Fayu Wan, Jamel Nebhen, Nour Mohammad Murad, Jérôme Rossignol, Sebastien Lallechere, and Blaise Ravelo. "Bandpass NGD investigation of O-shape fully distributed structure with S-matrix modelling." COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 40, no. 3 (July 14, 2021): 640–59. http://dx.doi.org/10.1108/compel-01-2021-0019.
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Purpose The aim of this paper is to provide the theoretical conceptualization of a bandpass (BP) negative group delay (NGD) microstrip circuit. The main objective is to provide a theorization of the particular geometry of the microstrip circuit with experimental validation of the NGD effect. Design/methodology/approach The methodology followed in this work is organized in three steps. A theoretical model is established of equivalent S-parameters model using Y-matrix analysis. The GD analysis is also presented by showing that the circuit presents a possibility to generate NGD function around certain frequencies. To validate the theoretical model, as proof-of-concept (POC), a microstrip prototype is designed, fabricated and tested. Findings This work clearly highlighted the modelled (analytical design model), simulated (ADS simulation tool) and measured results are in good correlation. Relying on the proposed theoretical, numerical and experimental models, the BP NGD behaviour is validated successfully with GD responses specified by the NGD centre frequency: it is observed around 2.35 GHz, with an NGD value of about −2 ns. Research limitations/implications It is to be noticed the proposed GD analysis requires limitations of the theoretical NGD model. It is depicted and validated through a POC demonstrating that the circuit presents a possibility to generate NGD function around certain frequencies (assuming constraints around usable frequency and bandwidth). Practical implications The NGD O-shape topology developed in this work could be exploited in the future in the microwave and radiofrequency context. Thus, it is expected to develop GD equalization technique for radiofrequency and microwave filters, GD compensation of oscillators, filters and communication systems, design of broadband switch-less bi-directional amplifiers, efficient enhancement of feedforward amplifiers, design method of frequency independent phase shifters with negligible delay, synthesis method of arbitrary-angle beamforming antennas. The BP NGD behavior may also be successfully used for the reduction of resonance effect for the electronic compatibility (EMC) of electronic devices. Social implications The non-conventional NGD O-circuit theoretical development and validation through experimental POC could be exploited by academic and industrial developers in the area of wireless communications including, but not restricted to, 5-generation communication systems. The use of the remarkable NGD effect is also useful for the mitigation of electromagnetic interferences between electronic devices and more and more complex electromagnetic environment (current development of Internet of Things[ IoT]). Originality/value The originality of this work relies on the new NGD design proposed in this work including the extraction of S-matrix parameters of the microstrip novel structure designed. The validation process based upon an experimental POC showed very interesting levels of NGD O-circuit (nanosecond-GD duration).
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Iskander, M. F., and Zhengqing Yun. "Propagation prediction models for wireless communication systems." IEEE Transactions on Microwave Theory and Techniques 50, no. 3 (March 2002): 662–73. http://dx.doi.org/10.1109/22.989951.
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Babaei, Mohammadreza, Lütfiye Durak-Ata, and Ümit Aygölü. "New Practical Nonlinear Energy-Harvesting Models for Wireless-Powered Communications." Wireless Communications and Mobile Computing 2022 (June 25, 2022): 1–19. http://dx.doi.org/10.1155/2022/6534754.
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As a massive number of nodes are expected to be connected to each other in next-generation wireless networks, the power supply of such multiple-antenna nodes is a challenge and requires new and sustainable solutions. Radio frequency energy harvesting (EH) is among the promising approaches to solve this issue. In this paper, two new mathematically tractable nonlinear EH (NL-EH) models are proposed, for which the system performance is evaluated in terms of average harvested power, throughput, and bit error probability. The system consists of one multiantenna power-constraint source harvesting its power from a dedicated power beacon and transmitting its signal to a destination equipped with multiple antennas. For a comprehensive analysis of the system, closed-form expressions are derived for Nakagami- m fading channels and the special case of Rayleigh channels. For comparison purposes, the performance derivations in Nakagami- m fading channels are provided for linear and piece-wise linear EH models given in the literature. Besides, the simulation results are obtained by applying the Monte-Carlo method for NL-EH models existing in the literature. The results provide a broadening view of EH systems and thoroughly compare the proposed NL-EH models with linear, piece-wise linear, and NL-EH models available in the literature. Hence, these provide better insights towards the analyses and design of EH systems.
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Verzun, Natalya, Mikhail Kolbanev, and Alexey Shamin. "The Architecture of the Access Protocols of the Global Infocommunication Resources." Computers 9, no. 2 (June 9, 2020): 49. http://dx.doi.org/10.3390/computers9020049.
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One of the important functions of cyberspace is to provide people and devices with access to global infocommunication resources, and as the network infrastructure develops, the number of access options increases, including those based on wireless technologies. A wide variety of access technologies leads to the formation of heterogeneous broadcast networks. Following the concept of Always Best Connected and striving for rational use of access network resources, developers use Vertical Handover procedures today. This approach assumes the existence of a selection criterion that allows you to prefer a particular network to other networks from the number of available and able to provide the required connection and services, and a selection procedure that implements the process of calculating the characteristics of access in each of the acceptable options. When implementing a vertical handover, it should be taken into account that the rational choice depends on the moment of time and point of space at which the terminal device developed a request to establish a connection. The corresponding procedures can be implemented in accordance with decentralized or centralized architectures. In the first case, the choice is made by hardware and software of terminal devices. The disadvantage of this implementation is the complexity and, as a result, the rise in price of terminal devices, each of which requires a corresponding complexity of the selection procedure of the performance and memory reserve. Another negative consequence of the decentralized approach is a decrease in the last-mile network utilization rate due to the inability to make complex decisions. The article discusses the centralized architecture of access protocols to global infocommunication resources. In accordance with it, the access network is selected by a new centralized network device that was not previously used on communication networks. The protocols that this network element implements should be located between the first (physical) and second (channel) levels of the open system interaction model. The purpose of the study is to develop an effective architectural solution for access networks and create a mathematical model for evaluating the efficiency of using the last mile resources and the quality of user service. The object of research is architectural solutions for last-mile networks. The subject of research is models of the theory of tele-traffic that allow us to evaluate the qualitative characteristics of the corresponding process. To achieve this goal the following tasks were solved in the article: analysis of known approaches to selecting one of several available access networks; development of a centralized architecture that changes the basic model of interaction between open systems; description of the metadata exchange scenario between network elements of the new architecture; development of a mathematical model of the data transmission process in the access radio network; conducting numerical estimates of the probabilistic and temporal characteristics of the proposed procedures.
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Krupanek, Beata, and Ryszard Bogacz. "Mathematical Model of Communication Delays in Wireless Networks." International Journal of Electronics and Telecommunications 62, no. 1 (March 1, 2016): 61–64. http://dx.doi.org/10.1515/eletel-2016-0008.
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Abstract The paper presents a new conception of building probabilistic models of communication delays in wireless networks that basis on using a delta function sequence to describe retransmissions between a transmitter and a receiver. It is assumed that the access time of the transmitter is described by a probability density function and the communication channel established in the wireless medium is disturbed by passive or active factors which cause that the transmission can be not correct and the sent data have to be retransmitted. Theoretical considerations have been verified by measurement results obtained by using the experimental system developed for investigating delays caused by external disturbances influencing the wireless transmission. A method of identification of the proposed model parameters and verification of the identified values has been presented.
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Imoize, Agbotiname Lucky, Augustus Ehiremen Ibhaze, Aderemi A. Atayero, and K. V. N. Kavitha. "Standard Propagation Channel Models for MIMO Communication Systems." Wireless Communications and Mobile Computing 2021 (February 15, 2021): 1–36. http://dx.doi.org/10.1155/2021/8838792.
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The field of wireless communication networks has witnessed a dramatic change over the last decade due to sophisticated technologies deployed to satisfy various demands peculiar to different data-intensive wireless applications. Consequently, this has led to the aggressive use of the available propagation channels to fulfill the minimum quality of service (QoS) requirement. A major barometer used to gauge the performance of a wireless communication system is the spectral efficiency (SE) of its communication channels. A key technology used to improve SE substantially is the multiple input multiple output (MIMO) technique. This article presents a detailed survey of MIMO channel models in wireless communication systems. First, we present the general MIMO channel model and identified three major MIMO channel models, viz., the physical, analytical, and standardized models. The physical models describe the MIMO channel using physical parameters. The analytical models show the statistical features of the MIMO channel with respect to the measured data. The standardized models provide a unified framework for modern radio propagation architecture, advanced signal processing, and cutting-edge multiple access techniques. Additionally, we examined the strengths and limitations of the existing channel models and discussed model design, development, parameterization, implementation, and validation. Finally, we present the recent 3GPP-based 3D channel model, the transitioning from 2D to 3D channel modeling, discuss open issues, and highlight vital lessons learned for future research exploration in MIMO communication systems.
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Levin, M. Sh. "On Combinatorial Models of Generations of Wireless Communication Systems." Journal of Communications Technology and Electronics 63, no. 6 (June 2018): 667–79. http://dx.doi.org/10.1134/s1064226918060165.
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Zhang, Zhijun, Z. Yun, and M. F. Iskander. "Ray tracing method for propagation models in wireless communication systems." Electronics Letters 36, no. 5 (2000): 464. http://dx.doi.org/10.1049/el:20000345.
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Ferreira, J. T., A. Bekker, F. Marques, and M. Laidlaw. "An Enriched α − μ Model as Fading Candidate." Mathematical Problems in Engineering 2020 (April 25, 2020): 1–9. http://dx.doi.org/10.1155/2020/5879413.
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This paper introduces an enriched α − μ distribution which may act as fading model with its origins via the scale mixture construction. The distribution’s characteristics are visited and its feasibility as a fading candidate in wireless communications systems is investigated. The analysis of the system reliability and some performance measures of wireless communications systems over this enriched α − μ fading candidate are illustrated. Computable representations of the Laplace transform for this scale mixture construction are also provided. The derived expressions are explored via numerical investigations. Tractable results are computed in terms of the Meijer G-function. This unified scale mixture approach allows access to previously unconsidered underlying models that may yield improved fits to experimental data in practice.
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Hüseyn oğlu Məmmədov, Famil. "Mathematical models of wireless local communication networks and methods of calculation of probability-time characteristics." SCIENTIFIC WORK 75, no. 2 (February 18, 2022): 148–54. http://dx.doi.org/10.36719/2663-4619/75/148-154.
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802.11 standartı və CSMA/CA protokolu əsasında qurulmuş simsiz lokal rabitə şəbəkələrinə baxılır. Baxılan şəbəkələr üzrə verilənlərin ötürülməsi zam- anı yaranan fiziki və ehtimal prosesləri nəzərə almaqla z-çevirməsi əsasında, onların riyazi modeli işlənmışdir. Bu model əsasında bilavasitə birləşmə və gözləmə prinsipli həlledicili əks əlaqəli alqoritmılərdən istifadə etməklə baxılan şəbəkələrin riyazi modelləri və ehtimal-zaman xarakteristikalarının hesablanması metodları işlənmişdir. Açar sözlər: simsiz lokal rabitə şəbəkələr, 802.11 stanrartı, CSMA/CA protokolu, z-çevirməsi, riyazi modellər, ehtimal-zaman xarakteristikaları Famil Huseyn Mammadov Mathematical models of wireless local communication networks and methods of calculation of probability-time characteristics Summary Wireless LANs based on the 802.11 standard and the CSMA/CA protocol are considered. Based on the z-transformation of the data in the networks in question, their mathematical models were developed, taking into account the physical and probabilistic processes that occur during their transmission. On this model, mathematical models and methods for calculating the probability-time characteristics of the networks under consideration were developed using directly connected and expectant decision feedback algorithms. Key words: wireless local area networks, 802.11 standard, CSMA/CA protocol, z-conversion, mathematical models, probability-time characteristics.
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Tran, Van Duy, Duc Khai Lam, and Thi Hong Tran. "Hardware-Based Architecture for DNN Wireless Communication Models." Sensors 23, no. 3 (January 23, 2023): 1302. http://dx.doi.org/10.3390/s23031302.
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Multiple Input Multiple Output Orthogonal Frequency Division Multiplexing (MIMO OFDM) is a key technology for wireless communication systems. However, because of the problem of a high peak-to-average power ratio (PAPR), OFDM symbols can be distorted at the MIMO OFDM transmitter. It degrades the signal detection and channel estimation performance at the MIMO OFDM receiver. In this paper, three deep neural network (DNN) models are proposed to solve the problem of non-linear distortions introduced by the power amplifier (PA) of the transmitters and replace the conventional digital signal processing (DSP) modules at the receivers in 2 × 2 MIMO OFDM and 4 × 4 MIMO OFDM systems. Proposed model type I uses the DNN model to de-map the signals at the receiver. Proposed model type II uses the DNN model to learn and filter out the channel noises at the receiver. Proposed model type III uses the DNN model to de-map and detect the signals at the receiver. All three model types attempt to solve the non-linear problem. The robust bit error rate (BER) performances of the proposed receivers are achieved through the software and hardware implementation results. In addition, we have also implemented appropriate hardware architectures for the proposed DNN models using special techniques, such as quantization and pipeline to check the feasibility in practice, which recent studies have not done. Our hardware architectures are successfully designed and implemented on the Virtex 7 vc709 FPGA board.
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Punt, J. B., D. Sparreboom, F. Brouwer, and R. Prasad. "Mathematical analysis of dynamic channel selection in indoor mobile wireless communication systems." IEEE Transactions on Vehicular Technology 47, no. 4 (1998): 1302–13. http://dx.doi.org/10.1109/25.728520.
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Unterhuber, Paul, Stephan Pfletschinger, Stephan Sand, Mohammad Soliman, Thomas Jost, Aitor Arriola, Iñaki Val, et al. "A Survey of Channel Measurements and Models for Current and Future Railway Communication Systems." Mobile Information Systems 2016 (2016): 1–14. http://dx.doi.org/10.1155/2016/7308604.
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Modern society demands cheap, more efficient, and safer public transport. These enhancements, especially an increase in efficiency and safety, are accompanied by huge amounts of data traffic that need to be handled by wireless communication systems. Hence, wireless communications inside and outside trains are key technologies to achieve these efficiency and safety goals for railway operators in a cost-efficient manner. This paper briefly describes nowadays used wireless technologies in the railway domain and points out possible directions for future wireless systems. Channel measurements and models for wireless propagation are surveyed and their suitability in railway environments is investigated. Identified gaps are pointed out and solutions to fill those gaps for wireless communication links in railway environments are proposed.
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Riurean, Simona. "Design and Evaluation of Visible Light Wireless Data Communication Models." Journal of Digital Science 2, no. 2 (December 29, 2020): 3–13. http://dx.doi.org/10.33847/2686-8296.2.2_1.
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The technologies based on the radio frequency used for wireless transmission indoor are more congested than ever these days, therefore several wireless communication alternatives are intensively searched. Some most promising technologies are based on the optical part of the electromagnetic spectrum. The benefits and drawbacks in optical wireless data communication models design are presented in this work. The key characteristics of the VLC systems are briefly discussed, as well. Some models developed for wireless data transfer in visible light communication and infrared are presented, and their operation related to the data rate and the length of the optical link, are briefly compared.
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S, SKRYPNYK, and KOLLAROV O. "Research of the impact of the introduction of neural networks in the energy sector of Ukraine." Journal of Electrical and power engineering 26, no. 4 (May 24, 2022): 39–43. http://dx.doi.org/10.31474/2074-2630-2022-1-39-43.
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A power plant converts energy from a non-electric form to an electric one. Depending on the energy conversion, power plants are classified as minerals, nuclear, solar, geothermal, hydroelectric, and so on. The main goal is to perform this transformation as best as possible. Criteria of safety, efficiency, reliability and affordability are taken into account as benchmarks. The station consists of several units that generate and work together to meet electricity needs. For a fossil fuel power plant, each unit consists of three main components: a boiler, a turbine and a generator. The complexity of the operation is due to the variability of the load and high efficiency required in a wide range of operations. The main difficulties for the management task then arise due to the strong link between process variables and process nonlinearity. The purpose of this article is to analyze and develop a proposal for the introduction of artificial intelligence in the power industry of Ukraine. To achieve this goal, we will offer the following tasks: - analyze existing systems for the use of artificial intelligence in industry; - develop proposals for the introduction of artificial intelligence in the electricity system of Ukraine. In this study, methods of statistical, factorial, historical, comparative, logical, economic-mathematical and systems analysis, the method of expert assessments were used, which allowed to formulate proposals for the introduction of artificial intelligence in the power industry. Artificial neural networks are the first step towards a fundamentally new system of information analysis. They are mathematical and computer models that simulate the work of biological neurons, ie a system of interacting processes, built on the principle of connecting nerve cells of the human brain. It should be noted that they differ from conventional machine algorithms in the ability to learn, memorize and reproduce images, determine patterns, memorize and analyze information and obtain results. Output signals that arrive at the next processor and continue to be converted. Thus, artificial neurons form networks and layers in which connections are created, restored, maintained and destroyed by special signals. With regard to artificial intelligence, there is no generally accepted definition of artificial intelligence, therefore, by artificial intelligence we mean a machine system capable of learning using objective knowledge and experience, to solve creative problems like the human brain and inventive tasks, not going through options, build strategies and apply abstract concepts. Digitalization and artificial intelligence are penetrating most sectors of the economy, including the electricity sector. The digitalization of energy requires the development and widespread use of end-to-end technologies, including industrial Internet, components of robotics, wireless communications, artificial intelligence and others. Thus, artificial intelligence technologies have prospects for development. Of course, significant targeted funding is needed to achieve significant results. The interaction of research institutes and universities with business is very important, where artificial intelligence technologies are also being developed. Attention of the authorities and society, their understanding of the importance of the tasks facing countries to achieve the goal of implementing artificial intelligence. With regard to electricity, the integration of artificial intelligence into the industry will help optimize and increase efficiency in all aspects of energy production, transmission and consumption. It should be noted that the development of electricity is a step towards the development of other industries. That is why the transition to the digital industry is impossible without the digitalization and intellectualization of the power industry
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Shen, Ying. "Wireless Sensor Network-Based Mathematical Modeling for Communication Intelligent Monitoring System." Journal of Sensors 2021 (November 5, 2021): 1–11. http://dx.doi.org/10.1155/2021/7809932.
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Knowing the behavioral patterns of city residents is of great value in formulating and adjusting urban planning strategies, such as urban road planning, urban commercial development, and urban pedestrian flow control. Based on the high penetration rate of cell phones, it is possible to indirectly understand the behavior of city residents based on the call records of users. However, the behavioral patterns of large-scale users over a long period of time can present characteristics such as large dispersion, difficult to discover patterns, and difficult to explain behavioral patterns. In this paper, we design and implement a human behavior pattern analysis system based on massive mobile communication data based on serial data modeling method and visual analysis technology. For the problem that it is difficult to capture the behavioral patterns of residents in cities in call records, this paper constructs base station trajectories based on users’ cell phone call records and uses users’ long-time base station trajectories to mine users’ potential behavioral patterns. Since users with similar activity characteristics will exhibit similar base station trajectories, this paper focuses on the similarity between text sequences and base station trajectory sequences and combines the word embedding method in natural language processing to build a Cell2vec model to identify the semantics of base stations in cities. In order to obtain the group behavior patterns of users from the base station trajectories of group users, a user clustering method based on users’ regional mobile preferences is proposed, and the results are projected using the Stochastic Neighbor Embedding (t-SNE) algorithm to expose the clustering features of large-scale cell phone users in the low-dimensional space. To address the problem that user behavior patterns are difficult to interpret, a visual analysis model with group as well as regional semantics is designed for the spatial and temporal characteristics of user behavior. Among them, the clustering model uses the distance between scatter points to map the similarity between users, which helps analysts to explore the behavioral characteristics of group users.
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Saed, Steve, Lingxi Li, and Dongsoo S. Kim. "Decentralized Average Consensus in Wireless Sensor Networks with Unreliable Communication Channels." International Journal of Handheld Computing Research 3, no. 3 (July 2012): 35–52. http://dx.doi.org/10.4018/jhcr.2012070103.
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This study proposes and evaluates an average consensus scheme for wireless sensor networks. For this, two communication error models, the fading signal error model and approximated fading signal error model, are introduced and incorporated into the proposed decentralized average consensus scheme, especially adapted to the constraints of wireless sensor networks. A mathematical analysis is introduced to derive the approximated fading signal model from the fading signal model and different simulation scenarios are introduced and their results analyzed to evaluate the performance of the proposed scheme and its effectiveness in meeting the needs of wireless sensor networks.
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Zheng, Kan, Suling Ou, and Xuefeng Yin. "Massive MIMO Channel Models: A Survey." International Journal of Antennas and Propagation 2014 (2014): 1–10. http://dx.doi.org/10.1155/2014/848071.
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The exponential traffic growth of wireless communication networks gives rise to both the insufficient network capacity and excessive carbon emissions. Massive multiple-input multiple-output (MIMO) can improve the spectrum efficiency (SE) together with the energy efficiency (EE) and has been regarded as a promising technique for the next generation wireless communication networks. Channel model reflects the propagation characteristics of signals in radio environments and is very essential for evaluating the performances of wireless communication systems. The purpose of this paper is to investigate the state of the art in channel models of massive MIMO. First, the antenna array configurations are presented and classified, which directly affect the channel models and system performance. Then, measurement results are given in order to reflect the main properties of massive MIMO channels. Based on these properties, the channel models of massive MIMO are studied with different antenna array configurations, which can be used for both theoretical analysis and practical evaluation.