无线工程与技术(英文)最新文献_第2页

Design of Ellipse Antenna Array for Cellular Phone Localization Systems 用于手机定位系统的椭圆天线阵列设计

无线工程与技术(英文) Pub Date : 2020-04-30 DOI: 10.4236/wet.2020.112002

Ahmad El Sayed Ahmad, J. Floch, A. Choumane, P. Morgand

引用次数: 1

Emulation of Realistic Multi-Path Propagation Channels inside an Anechoic Chamber for Antenna Diversity Measurements 天线分集测量中暗室内真实多径传播信道的仿真

无线工程与技术(英文) Pub Date : 2020-01-30 DOI: 10.4236/wet.2020.111001

A. Choumane, Ahmad El Sayed Ahmad, K. Khoder

{"title":"Emulation of Realistic Multi-Path Propagation Channels inside an Anechoic Chamber for Antenna Diversity Measurements","authors":"A. Choumane, Ahmad El Sayed Ahmad, K. Khoder","doi":"10.4236/wet.2020.111001","DOIUrl":"https://doi.org/10.4236/wet.2020.111001","url":null,"abstract":"As antennas are inherently included recommended in Over-The-Air (OTA) testing, it is important to also consider realistic channel models for the multiple-input multiple-output (MIMO) device performance evaluation. This paper aims to emulate realistic multi-Path propagation channels in terms of angles of arrivals (AoA) and cross-polarization ratio (XPR) with Rayleigh fading, inside an anechoic chamber, for antenna diversity measurements. In this purpose, a practical multi-probe anechoic chamber measurement system (MPAC) with 24 probe antennas (SATIMO SG24) has been used. However, the actual configuration of this system is not able to reproduce realistic channels. Therefore, a new method based on the control of the SG24 probes has been developed. At first time, this method has been validated numerically through the comparison of simulated and analytical AoA probability density distributions. At the second time, the performance of an antenna diversity system inside the SG24 has been performed in terms of the correlation coefficient and diversity gain (DG) using an antenna reference system. Simulated and measurements results have shown a good agreement.","PeriodicalId":68067,"journal":{"name":"无线工程与技术(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45066310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Differential Cross-Polarized Wireless Communications 差分交叉极化无线通信

无线工程与技术(英文) Pub Date : 2019-04-28 DOI: 10.4236/WET.2019.102003

S. Ghadimi

引用次数: 1

Design of Printed Dipole Array for Omnidirectional Radiation Pattern 面向全向辐射方向图的印刷偶极子阵列设计

无线工程与技术(英文) Pub Date : 2019-03-06 DOI: 10.4236/WET.2019.102002

J. Floch

引用次数: 4

The Roles of Information and Communication Technologies (ICTs) and E-Commerce as Agents of Nigeria’s Economic Development: Review of Challenges and Prospects 信息通信技术(ict)和电子商务在尼日利亚经济发展中的作用:挑战与前景回顾

无线工程与技术(英文) Pub Date : 2019-01-01 DOI: 10.4236/wet.2019.103004

B. Joseph

引用次数: 4

Environmental Monitoring Systems: Review and Future Development 环境监察系统:回顾与未来发展

无线工程与技术(英文) Pub Date : 2019-01-01 DOI: 10.4236/wet.2019.101001

I. Šećerov, D. Dolinaj, D. Pavić, D. Milošević, S. Savić, Srdan Popov, Zarko Zivanov

{"title":"Environmental Monitoring Systems: Review and Future Development","authors":"I. Šećerov, D. Dolinaj, D. Pavić, D. Milošević, S. Savić, Srdan Popov, Zarko Zivanov","doi":"10.4236/wet.2019.101001","DOIUrl":"https://doi.org/10.4236/wet.2019.101001","url":null,"abstract":"Monitoring and recording large time series of data and making them available for studying—are the key roles of environmental monitoring systems. This study produce review of three different measurement monitoring systems (NSUNET, WAHASTRAT and MERIEXWA) with same design, which were placed during different time frame in the Northern Serbia (Vojvodina Province). Each of three monitoring systems has different demands and requirements which were addressed accordingly in their design. Power supply conditions for two systems are primary cells and solar panels, while NSUNET has constant power supply only during nighttime. Data is transmitted in MERIEXWA using binary protocol, WAHASTRAT using http, while NSUNET sends data over ftp. Same topology is used in all systems—each node sends data directly to the central location (in case of NSUNET two locations are provided for backup purposes). NSUNET system sends data using specific structure and stores them as plain text files. It also has different approach for time synchronization and monitoring issues. The main result of this study is to present how to create system that provides good quality and unchanged data from monitoring sensor to the end user while maintaining whole data structure transmission costs low. Furthermore, data collected from NSUNET were used in order to assess the influence of urbanization on regional climate modification, which leads to the creation of urban climate. Propositions for new system development combining best from all three systems are discussed.","PeriodicalId":68067,"journal":{"name":"无线工程与技术(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70839589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 15

Classification Approach for Intrusion Detection in Vehicle Systems 车辆系统入侵检测的分类方法

无线工程与技术(英文) Pub Date : 2018-10-08 DOI: 10.4236/WET.2018.94007

Abdulaziz Alshammari, M. Zohdy, D. Debnath, George P. Corser

{"title":"Classification Approach for Intrusion Detection in Vehicle Systems","authors":"Abdulaziz Alshammari, M. Zohdy, D. Debnath, George P. Corser","doi":"10.4236/WET.2018.94007","DOIUrl":"https://doi.org/10.4236/WET.2018.94007","url":null,"abstract":"Vehicular ad hoc networks (VANETs) enable wireless communication among Vehicles and Infrastructures. Connected vehicles are promising in Intelligent Transportation Systems (ITSs) and smart cities. The main ob-jective of VANET is to improve the safety, comfort, driving efficiency and waiting time on the road. VANET is unlike other ad hoc networks due to its unique characteristics and high mobility. However, it is vulnerable to various security attacks due to the lack of centralized infrastructure. This is a serious threat to the safety of road traffic. The Controller Area Network (CAN) is a bus communication protocol which defines a standard for reliable and efficient transmission between in-vehicle parts simultaneously. The message moves through CAN bus from one node to another node, but it does not have information about the source and destination address for authentication. Thus, the attacker can easily inject any message to lead to system faults. In this paper, we present machine learning techniques to cluster and classify the intrusions in VANET by KNN and SVM algorithms. The intrusion detection technique relies on the analysis of the offset ratio and time interval between the messages request and the response in the CAN.","PeriodicalId":68067,"journal":{"name":"无线工程与技术(英文)","volume":"09 1","pages":"79-94"},"PeriodicalIF":0.0,"publicationDate":"2018-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45651425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 57

On Evaluating the Efficacy of Predictive Models for Cognitive Radio Spectrum Availability in Nigeria 尼日利亚认知无线电频谱可用性预测模型的有效性评估

无线工程与技术(英文) Pub Date : 2018-07-13 DOI: 10.4236/wet.2018.93005

S. Okegbile, A. Oluwaranti, Segun Aina

{"title":"On Evaluating the Efficacy of Predictive Models for Cognitive Radio Spectrum Availability in Nigeria","authors":"S. Okegbile, A. Oluwaranti, Segun Aina","doi":"10.4236/wet.2018.93005","DOIUrl":"https://doi.org/10.4236/wet.2018.93005","url":null,"abstract":"In order to avoid the undesired interference with the activities of the primary users in cognitive radio networks, the secondary users are required to be able to predict the behavior of the primary users so as to leave the channel before the arrival of such licensed owner of the spectrum. While a number of existing literatures on cognitive radio spectrum prediction employ the use of propagation curves for predicting the spectrum holes otherwise known as TV white space, these models are built based on measurements conducted in regions that are different from Nigeria, suitability in terms of usage may therefore vary due to environmental factors and terrain profile. This work evaluates the efficacy of the developed model in predicting the cognitive spectrum availability in Nigeria. Models capable of predicting spectrum occupancy in the time domain using discrete-time two-state Markov chain with an appropriate Duty Cycle (DC) model and also a modified m-bell shaped exponential equation were formulated. The result obtained in all cases considered shows that the formulated models are appropriate to be used in any environment if the parameters were carefully extracted from the data. This work has also demonstrated that the accuracy of Markov chain models depends on the level of usage of a spectrum under consideration and may therefore not give desirable results when employed in some other spectrum.","PeriodicalId":68067,"journal":{"name":"无线工程与技术(英文)","volume":"09 1","pages":"49-65"},"PeriodicalIF":0.0,"publicationDate":"2018-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42059705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Aperture Efficiency Study of Square Reflect Array Antennas 方形反射阵列天线孔径效率研究

无线工程与技术(英文) Pub Date : 2018-07-13 DOI: 10.4236/WET.2018.93006

J. Nourinia, C. Ghobadi, B. Mohammadi, F. Alizadeh

引用次数: 4

Hybrid IEEE 802.15.6 Wireless Body Area Networks Interference Mitigation Model for High Mobility Interference Scenarios 高移动性干扰场景下的混合IEEE 802.15.6无线体域网络干扰缓解模型

无线工程与技术(英文) Pub Date : 2018-04-09 DOI: 10.4236/wet.2018.92004

Anthony Mile, G. Okeyo, Ann Kibe

{"title":"Hybrid IEEE 802.15.6 Wireless Body Area Networks Interference Mitigation Model for High Mobility Interference Scenarios","authors":"Anthony Mile, G. Okeyo, Ann Kibe","doi":"10.4236/wet.2018.92004","DOIUrl":"https://doi.org/10.4236/wet.2018.92004","url":null,"abstract":"The field of Wireless Sensor Networks (WSNs) has revolutionized tremendously in the recent past with its major application in Wireless Body Area Networks (WBANs). This has in the same dimension attracted immense interests from the researchers and technology providers. The operational modality of the WBANs is that a few sensor nodes are placed in or around the body and that they are meant to operate within a limited condition while providing high performance in terms of WBAN life time, high throughput, high data reliability, minimum or no delay and low power consumption. As most of the WBAN operates within the universal Industrial, Scientific and Medical (ISM) Narrow Band (NB) wireless band (2.4 Ghz) frequency band, this has posed a challenge in respect to inter, intra and co-channel interference especially in dense areas and high mobility scenarios. As well the body posture changes dynamically due to these mobility effects. In this paper, we propose a hybrid WBAN interference mitigation model based on Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) Contention Window (CW) approach and User Priority (UP) queues. Using Omnet++ simulation, a comparison to the IEEE 802.15.6 based WBAN protocol is presented under the standing, walking sitting and Lying postural mobility scenarios. The results show that the proposed hybrid model outperforms IEEE 802.15.6 based CSMA/CA protocol in areas of network throughput, bandwidth efficiency and network delay in these mobility postures.","PeriodicalId":68067,"journal":{"name":"无线工程与技术(英文)","volume":"09 1","pages":"34-48"},"PeriodicalIF":0.0,"publicationDate":"2018-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43375405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 16