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Int. J. Wirel. Opt. Commun.最新文献

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Synchronized and Concurrent Enabling of Neighborhood Transmission (scent) - a MAC Protocol for Concurrent Transmission in Wireless Ad-Hoc Networks 同步和并发使能邻域传输——一种用于无线自组织网络并发传输的MAC协议
Int. J. Wirel. Opt. Commun. Pub Date : 2004-12-01 DOI: 10.1142/S0219799504000337
Jaya Shankar Pathmasuntharam, A. Das, A. Gupta
{"title":"Synchronized and Concurrent Enabling of Neighborhood Transmission (scent) - a MAC Protocol for Concurrent Transmission in Wireless Ad-Hoc Networks","authors":"Jaya Shankar Pathmasuntharam, A. Das, A. Gupta","doi":"10.1142/S0219799504000337","DOIUrl":"https://doi.org/10.1142/S0219799504000337","url":null,"abstract":"This paper presents a distributed and concurrent multiple access-based collision avoidance MAC scheme to increase spatial reuse and hence the overall throughput of wireless networks. We make use of location information and power capture techniques to realize this protocol. While other wireless MAC protocols have used power capture technique in a general manner to reject the interfering signals during the entire reception of a packet, we exploit the additional capability of power capture to \"lock-on\" to the intended packet during a period known as \"capture time\" to admit other parallel transmissions. Simulation results show that our protocol can outperform the IEEE 802.11 throughput performance by a factor of 2 or more when there are short and medium range transmissions within a given area.","PeriodicalId":185917,"journal":{"name":"Int. J. Wirel. Opt. Commun.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128234372","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
Statistical Properties of Urban WCDMA Channel for Mobile Positioning Applications 面向移动定位应用的城市WCDMA信道统计特性研究
Int. J. Wirel. Opt. Commun. Pub Date : 2004-12-01 DOI: 10.1142/S0219799504000283
E. Lohan, A. Lakhzouri, M. Renfors
{"title":"Statistical Properties of Urban WCDMA Channel for Mobile Positioning Applications","authors":"E. Lohan, A. Lakhzouri, M. Renfors","doi":"10.1142/S0219799504000283","DOIUrl":"https://doi.org/10.1142/S0219799504000283","url":null,"abstract":"The goal of this paper is to present the results of a comprehensive statistical analysis of the urban wireless channels, based on WCDMA field-measurements data. The applications of our study are in the area of WCDMA-based mobile phone positioning. The objective here is the analysis of the Line-of-Sight (LOS) and Non Line-of-Sight (NLOS) situations and the statistical distributions of their parameters, such as the delays and amplitudes. The distribution of the first arriving path is tested against several theoretical distributions, such as the Rayleigh, Rician, and Nakagami-m distributions. The estimated delay of the first arriving path is compared to the LOS delay estimated via GPS so as to detect NLOS situations. The estimation of the mobile speed based on field-measurements data is also carried out and compared to the speed estimation based on the GPS link. The measurements were conducted in urban environment, downtown Helsinki.","PeriodicalId":185917,"journal":{"name":"Int. J. Wirel. Opt. Commun.","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125595381","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: 3
Optimum Design of Broadband Branch-Line Couplers with Arbitrary Power Division and Impedance Transformation 具有任意功率划分和阻抗变换的宽带支路耦合器的优化设计
Int. J. Wirel. Opt. Commun. Pub Date : 2004-12-01 DOI: 10.1142/S0219799504000313
H. Oraizi, J. Hamedfar
{"title":"Optimum Design of Broadband Branch-Line Couplers with Arbitrary Power Division and Impedance Transformation","authors":"H. Oraizi, J. Hamedfar","doi":"10.1142/S0219799504000313","DOIUrl":"https://doi.org/10.1142/S0219799504000313","url":null,"abstract":"In this paper a numerical method is presented for the design and optimization of a broadband branch-line coupler for arbitrary power division between its output ports over a specified frequency band together with impedance matching of the source to the load impedances. First, the reflected and transmitted wave amplitudes at the four ports of the coupler are expressed in terms of its reflection and transmission coefficients, which are themselves written in terms of the scattering parameters and finally transmission matrix parameters in the even- and odd-mode analysis. Then an error function is constructed for the specified power division ratios in the desired frequency bandwidth including dispersion models. The minimization of error function determines the widths, spacings and lengths of the strip conductors. The frequency responses obtained from the computer programs and fabrication and measurement of two couplers indicate the effectiveness of the proposed method.","PeriodicalId":185917,"journal":{"name":"Int. J. Wirel. Opt. Commun.","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127220546","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: 2
A Compact Electronically Reconfigurable Dual Frequency Microstrip Antenna for L-Band Applications 用于l波段应用的紧凑型电子可重构双频微带天线
Int. J. Wirel. Opt. Commun. Pub Date : 2004-12-01 DOI: 10.1142/S0219799504000295
S. Shynu, Augustin Gijo, C. Aanandan, P. Mohanan, K. Vasudevan
{"title":"A Compact Electronically Reconfigurable Dual Frequency Microstrip Antenna for L-Band Applications","authors":"S. Shynu, Augustin Gijo, C. Aanandan, P. Mohanan, K. Vasudevan","doi":"10.1142/S0219799504000295","DOIUrl":"https://doi.org/10.1142/S0219799504000295","url":null,"abstract":"A novel design of a compact electronically reconfigurable dual frequency dual polarized single feed hexagonal slot loaded microstrip antenna in L-band is introduced in this paper. Pin diodes are used to switch the operating frequencies considerably, without much affecting the radiation characteristics and gain. The antenna can work with a frequency ratio varying in a wide range from 1.2 to 1.4. The proposed design has an added advantage of size reduction up to 72.21% and 46.84% for the two resonating frequencies, compared to standard rectangular patches. The design also gives considerable bandwidth of up to 2.82% and 2.42% for the two operating frequencies.","PeriodicalId":185917,"journal":{"name":"Int. J. Wirel. Opt. Commun.","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130871390","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: 7
Performance Comparison of Reactive Routing Protocols under Attack Conditions 攻击条件下响应式路由协议性能比较
Int. J. Wirel. Opt. Commun. Pub Date : 2004-12-01 DOI: 10.1142/S0219799504000271
A. Pirzada, C. McDonald
{"title":"Performance Comparison of Reactive Routing Protocols under Attack Conditions","authors":"A. Pirzada, C. McDonald","doi":"10.1142/S0219799504000271","DOIUrl":"https://doi.org/10.1142/S0219799504000271","url":null,"abstract":"Mobile ad-hoc wireless networks are established with the mutual cooperation of a number of nodes generally having meagre computing and communication resources. These nodes execute special routing protocols, which enable them to perform multi-hop communication in a dynamic topology. Each node virtually acts as a mobile router and routes packets for other nodes in the network. For accurate functioning of the network it is imperative that all nodes execute these routing protocols in a benevolent manner. However, as ad-hoc networks are usually established in a physically insecure wireless environment, the network memberships are every now and then violated, and so malicious nodes are able to participate in the network. These nodes can launch an array of attacks against different network services including the routing process. In this paper, we evaluate the performance of three well known reactive routing protocols, in a network with varying number of malicious nodes. With the help of exhaustive simulations, we demonstrate that the performance of the three protocols greatly varies with traffic load and mobility conditions even under similar attack conditions.","PeriodicalId":185917,"journal":{"name":"Int. J. Wirel. Opt. Commun.","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134095244","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
Possibility of Plastic Optical Fiber amplifiers doped with ER(C8h11f8o2)3 掺ER(C8h11f8o2)的塑料光纤放大器的可能性
Int. J. Wirel. Opt. Commun. Pub Date : 2004-12-01 DOI: 10.1142/S021979950400026X
K. Fujii
{"title":"Possibility of Plastic Optical Fiber amplifiers doped with ER(C8h11f8o2)3","authors":"K. Fujii","doi":"10.1142/S021979950400026X","DOIUrl":"https://doi.org/10.1142/S021979950400026X","url":null,"abstract":"Plastic optical fiber amplifiers (POFAs), doped with Er(C8H11F8O2)3, having an energy system showing 3-level features have been investigated theoretically focusing on the condition for amplifying mainly the lowest signal mode (LP01 mode). We have studied the dependence of signal gain on fiber structure design for circular and ring doping conditions and have shown that the gain for the fundamental mode (LP01) and the second order mode (LP11 mode) is a strong function of the outer radius (ro) of the doping area. The gain for the LP01 mode becomes larger than that of LP11 mode when ro is less than 110 μm with doping concentration (N0) of 3 × 1020cm-3. A signal gain of 18.2 dB is predicted for LP01 mode for 9 cm long POFA with circular doping and ro of 80 μm when N0, the pump power and the core radius are 2.66 × 1020cm-3, 30 W and 250 μm, respectively. The gain is 12 dB larger than that for LP11 mode under the same condition.","PeriodicalId":185917,"journal":{"name":"Int. J. Wirel. Opt. Commun.","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114489523","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
Investigation of Planar Square Antennas for UWB Applications 面向超宽带应用的平面方形天线研究
Int. J. Wirel. Opt. Commun. Pub Date : 2004-12-01 DOI: 10.1142/S0219799504000301
Zhi Ning Chen, N. Yang, T. See, X. Qing
{"title":"Investigation of Planar Square Antennas for UWB Applications","authors":"Zhi Ning Chen, N. Yang, T. See, X. Qing","doi":"10.1142/S0219799504000301","DOIUrl":"https://doi.org/10.1142/S0219799504000301","url":null,"abstract":"The broadband planar square monopole/dipole antennas are characterized for ultra-wideband (UWB) applications. Due to the unique requirements from UWB applications, the design considerations, impedance, radiation, and transfer performance of the planar broadband antennas driven by impulses are examined numerically and validated experimentally. The study shows the important characteristics of broadband antennas in both time and frequency domains.","PeriodicalId":185917,"journal":{"name":"Int. J. Wirel. Opt. Commun.","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122108848","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
Design of Dispersion Flattened and Compensating Fibers for Dispersion-Managed Optical Communications Systems 色散管理光通信系统中色散平坦和补偿光纤的设计
Int. J. Wirel. Opt. Commun. Pub Date : 2004-06-01 DOI: 10.1142/S0219799504000210
L. Binh, T. Huynh, Kaui Chin, D. Sharma
{"title":"Design of Dispersion Flattened and Compensating Fibers for Dispersion-Managed Optical Communications Systems","authors":"L. Binh, T. Huynh, Kaui Chin, D. Sharma","doi":"10.1142/S0219799504000210","DOIUrl":"https://doi.org/10.1142/S0219799504000210","url":null,"abstract":"Single mode optical fibers with low non-zero dispersion over two optical wavelength windows of 1300 and 1550 nm regions are essential for multi-channel operation of dense and coarse WDM systems to minimize the linear pulse broadening and nonlinear four wave mixing effects. Non-zero dispersion flattening of the dispersion factor extending over a wavelength range of more than 350 nm is achievable. Further we present designs of non-zero low dispersion flattened fiber rand dispersion compensating fiber over the entire S- to L-bands spectral window. The design of a unity \"Kappa\" and a near-zero dispersion-length product for a 100 km dispersion-managed fiber span is demonstrated. The effects of the geometrical and index distribution parameters of triple-clad index profile on the fiber total dispersion are also considered. Design guidelines and identification of critical fiber parameters are provided.","PeriodicalId":185917,"journal":{"name":"Int. J. Wirel. Opt. Commun.","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125001261","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: 7
Performance of Frequency Hopped Noncoherent GFSK over Time-Varying Rayleigh Fading Channels 时变瑞利衰落信道下跳频非相干GFSK的性能研究
Int. J. Wirel. Opt. Commun. Pub Date : 2004-06-01 DOI: 10.1142/S0219799504000209
Huaping Liu, V. Venkatesan, M. Magaña, C. Nilsen, R. Kyker
{"title":"Performance of Frequency Hopped Noncoherent GFSK over Time-Varying Rayleigh Fading Channels","authors":"Huaping Liu, V. Venkatesan, M. Magaña, C. Nilsen, R. Kyker","doi":"10.1142/S0219799504000209","DOIUrl":"https://doi.org/10.1142/S0219799504000209","url":null,"abstract":"An analytical treatment of the performance of frequency hopped Gaussian frequency shift keying (GFSK) with differential detection in time-varying Rayleigh fading channels corrupted by additive white Gaussian noise (AWGN) is presented. Closed-form expressions for the bit error rate (BER) as a function of Eb/N0, modulation index, channel Doppler shift, and the time-bandwidth product of the pre-modulation filter are derived. A pilot symbol-assisted scheme to lower the error floor caused by frequency hopping is analyzed.","PeriodicalId":185917,"journal":{"name":"Int. J. Wirel. Opt. Commun.","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128402415","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
Fairness in WDM Optical Networks without Wavelength Conversions 无波长转换的WDM光网络公平性研究
Int. J. Wirel. Opt. Commun. Pub Date : 2004-06-01 DOI: 10.1142/S0219799504000258
Anwar Alyatama
{"title":"Fairness in WDM Optical Networks without Wavelength Conversions","authors":"Anwar Alyatama","doi":"10.1142/S0219799504000258","DOIUrl":"https://doi.org/10.1142/S0219799504000258","url":null,"abstract":"In this paper, we investigate the problem of fairness in Wavelength Division Multiplexing (WDM) networks without conversions. While most of the studies done concentrate on total network performance, little attention has been paid to fairness during the design of WDM networks. Fairness is a very serious issue in networks without conversions. The call blocking probabilities are very sensitive to the path length. We propose a near optimal fair capacity planning and fair routing and wavelength assignment (RWA) for WDM networks. Our approach is based on solving the call blocking probabilities for static routing with Random/First-Fit wavelength assignment algorithm. We use the Fairness Index and the total network performance as the objectives of our capacity planning and RWA design. The Fairness Index measures the fairness between all source/destination pairs. Simulated Annealing approach is used for capacity planning and RWA design.","PeriodicalId":185917,"journal":{"name":"Int. J. Wirel. Opt. Commun.","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117335716","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: 3
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