发布求助
文献互助 智能选刊 最新文献

Proceedings of the Eighteenth National Radio Science Conference. NRSC'2001 (IEEE Cat. No.01EX462)最新文献

筛选
英文 中文
Punctured trellis (P-Trellis) coded frequency/phase modulation in faded mobile satellite channels 消光移动卫星信道中穿孔栅格编码的频率/相位调制
Proceedings of the Eighteenth National Radio Science Conference. NRSC'2001 (IEEE Cat. No.01EX462) Pub Date : 2001-03-27 DOI: 10.1109/NRSC.2001.929395
R. El-awady, M.A. Bahie Eldin, L. F. Gergis
{"title":"Punctured trellis (P-Trellis) coded frequency/phase modulation in faded mobile satellite channels","authors":"R. El-awady, M.A. Bahie Eldin, L. F. Gergis","doi":"10.1109/NRSC.2001.929395","DOIUrl":"https://doi.org/10.1109/NRSC.2001.929395","url":null,"abstract":"A set of high-rate punctured convolutional codes can be implemented by the periodic elimination (puncturing) of a low rate 1/n of the original code. The main advantage for this system is that a single Viterbi decoder matched to the lower rate of the original code can be used to decode all higher rates obtained by puncturing this one code. This paper studies the performance of punctured trellis coded modulation of constant envelope frequency and phase (FPM) modulated signal sets for AWGN and fading mobile satellite channels. Results showed the superiority of proposed modulation scheme over other types of modulation.","PeriodicalId":123517,"journal":{"name":"Proceedings of the Eighteenth National Radio Science Conference. NRSC'2001 (IEEE Cat. No.01EX462)","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129706081","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
The effect of base stations configurations on the accuracy of hyperbolic position location in macrocellular and microcellular GSM systems 大蜂窝和微蜂窝GSM系统中基站配置对双曲位置定位精度的影响
Proceedings of the Eighteenth National Radio Science Conference. NRSC'2001 (IEEE Cat. No.01EX462) Pub Date : 2001-03-27 DOI: 10.1109/NRSC.2001.929240
Y.A. Abdulla, H. El-Hennawy, S. Mahrous
{"title":"The effect of base stations configurations on the accuracy of hyperbolic position location in macrocellular and microcellular GSM systems","authors":"Y.A. Abdulla, H. El-Hennawy, S. Mahrous","doi":"10.1109/NRSC.2001.929240","DOIUrl":"https://doi.org/10.1109/NRSC.2001.929240","url":null,"abstract":"One method of position location (PL) in cellular systems is based on measuring the time difference of arrival (TDOA) of signal received by three or more base stations. The received signals are cross-correlated to determine the TDOAs and a set of nonlinear equations is obtained and then solved to produce the location estimate. In this paper two algorithms, Taylor-series and Chan are used. They can provide a precise position estimate at reasonable noise levels. The Taylor-series is an iterative method, so it suffers from the convergence problem and is computationally intensive as the least squares (LS) computation is required in each iteration. Chan's method can provide a non-iterative closed form solution with the same accuracy as in the Taylor method and there is no convergence problem. Also the effect of number and arrangement of base stations on the accuracy of the hyperbolic position location based on TDOA techniques is investigated. This is performed for a range of base stations (BSs) (up to 7) and for two different configurations, macrocellular and microcellular environments in ideal and non-ideal arrangements.","PeriodicalId":123517,"journal":{"name":"Proceedings of the Eighteenth National Radio Science Conference. NRSC'2001 (IEEE Cat. No.01EX462)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130062797","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: 13
HMM/NN hybrids for continuous speech recognition HMM/NN混合连续语音识别
Proceedings of the Eighteenth National Radio Science Conference. NRSC'2001 (IEEE Cat. No.01EX462) Pub Date : 2001-03-27 DOI: 10.1109/NRSC.2001.929410
O. Abdel Alim, N. Elboghdadly, N.M. El Shaar
{"title":"HMM/NN hybrids for continuous speech recognition","authors":"O. Abdel Alim, N. Elboghdadly, N.M. El Shaar","doi":"10.1109/NRSC.2001.929410","DOIUrl":"https://doi.org/10.1109/NRSC.2001.929410","url":null,"abstract":"The main goal of automatic speech recognition (ASR) is to produce a machine which will recognize accurately normal human speech from any speaker. The recognition system may be classified as speaker-dependent or speaker-independent and isolated-word or connected word. There are three approaches to research in automatic speech recognition (ASR); the acoustic-phonetic approach, the pattern recognition approach, and the database statistical approach. Two approaches of this kind: hidden Markov model (HMM) and artificial neural network (ANN) are presented in this paper.","PeriodicalId":123517,"journal":{"name":"Proceedings of the Eighteenth National Radio Science Conference. NRSC'2001 (IEEE Cat. No.01EX462)","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129306137","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
Performance of DS/CDMA multiple picocellular mobile radio system employing RAKE receiver over Rician channel 采用RAKE接收机的DS/CDMA多皮蜂窝移动无线电系统性能研究
Proceedings of the Eighteenth National Radio Science Conference. NRSC'2001 (IEEE Cat. No.01EX462) Pub Date : 2001-03-27 DOI: 10.1109/NRSC.2001.929207
H. Al-Shennawy,, A. Al-Bassiouni, H. Mourad, E. Al-Hussaini
{"title":"Performance of DS/CDMA multiple picocellular mobile radio system employing RAKE receiver over Rician channel","authors":"H. Al-Shennawy,, A. Al-Bassiouni, H. Mourad, E. Al-Hussaini","doi":"10.1109/NRSC.2001.929207","DOIUrl":"https://doi.org/10.1109/NRSC.2001.929207","url":null,"abstract":"A practical model is presented for analyzing the reverse link (i.e. from the mobile stations (MSs) to the cell site (CS) of direct sequence code division multiple access (DS/CDMA) multiple picocellular radio system) using binary phase shift keying (BPSK) modulation and employing a RAKE receiver over a Rician channel. This paper analyses the error probabilities and shows that the amount of multiple access interference (MAI) and multipath fading have substantial effects on the system performance. It is shown that MAI can be reduced by sectorization and voice activity monitoring. Multipath fading can be mitigated by diversity. Implicit diversity is achieved using a RAKE receiver. Explicit diversity is obtained through the use of selection diversity of RAKE receivers.","PeriodicalId":123517,"journal":{"name":"Proceedings of the Eighteenth National Radio Science Conference. NRSC'2001 (IEEE Cat. No.01EX462)","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133703208","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
FDTD analysis of open-end microstrip transmission line fabricated on a nonreciprocal ferrite substrate 非互易铁氧体衬底上开放式微带传输线的时域有限差分分析
Proceedings of the Eighteenth National Radio Science Conference. NRSC'2001 (IEEE Cat. No.01EX462) Pub Date : 2001-03-27 DOI: 10.1109/NRSC.2001.929157
A. Mahmoud, A. Mitkees, H. Elmikati
{"title":"FDTD analysis of open-end microstrip transmission line fabricated on a nonreciprocal ferrite substrate","authors":"A. Mahmoud, A. Mitkees, H. Elmikati","doi":"10.1109/NRSC.2001.929157","DOIUrl":"https://doi.org/10.1109/NRSC.2001.929157","url":null,"abstract":"The analysis of open-end microstrip transmission line fabricated on ferrite substrate is presented. The finite difference time domain (FDTD) method with both modified Mur'sC981) first order absorbing boundary conditions (MMFOC) and material independent perfectly matched layer absorber (MIPML) is applied to determine the time domain field response and the phase constant of the proposed structure. In addition, the effect of changing both bias field strength and ferrite saturation magnetization are investigated. The results obtained by the FDTD with MMFOC and MIPIML are found to be in good agreement with the published data.","PeriodicalId":123517,"journal":{"name":"Proceedings of the Eighteenth National Radio Science Conference. NRSC'2001 (IEEE Cat. No.01EX462)","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116250385","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
GNNFRM: Genetically constructed neuro new fuzzy reasoning model GNNFRM:遗传构建的神经模糊推理新模型
Proceedings of the Eighteenth National Radio Science Conference. NRSC'2001 (IEEE Cat. No.01EX462) Pub Date : 2001-03-27 DOI: 10.1109/NRSC.2001.929390
M. Tayel, M. Gamal Eldin Ahmed
{"title":"GNNFRM: Genetically constructed neuro new fuzzy reasoning model","authors":"M. Tayel, M. Gamal Eldin Ahmed","doi":"10.1109/NRSC.2001.929390","DOIUrl":"https://doi.org/10.1109/NRSC.2001.929390","url":null,"abstract":"In this paper, a genetic algorithm with adaptive probabilities of crossover and mutation is introduced to find near global optimum parameters for the Neuro-new fuzzy reasoning model (NNFRM). The parameters to be optimized are those of input membership functions, output membership functions and relation matrix. A fuzzy evaluation criterion is introduced to evaluate the different fuzzy models. This criterion stresses the fact that the fuzzy system must be comprehensible and transparent to the user. The performance of the proposed model is evaluated using a benchmark problem. Also, the generalization of the proposed model is compared to the feed forward neural network. It is shown that the proposed GNNFRM outperforms other modeling methods. The generalization of the proposed model is better than that of the feed forward neural network.","PeriodicalId":123517,"journal":{"name":"Proceedings of the Eighteenth National Radio Science Conference. NRSC'2001 (IEEE Cat. No.01EX462)","volume":"04 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127192353","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
Separation method in the problem of a beam-plasma interaction in bounded warm plasma under the effect of HF electric field 高频电场作用下有界热等离子体束等离子体相互作用问题的分离方法
Proceedings of the Eighteenth National Radio Science Conference. NRSC'2001 (IEEE Cat. No.01EX462) Pub Date : 2001-03-27 DOI: 10.1109/NRSC.2001.929422
K. El-Shorbagy
{"title":"Separation method in the problem of a beam-plasma interaction in bounded warm plasma under the effect of HF electric field","authors":"K. El-Shorbagy","doi":"10.1109/NRSC.2001.929422","DOIUrl":"https://doi.org/10.1109/NRSC.2001.929422","url":null,"abstract":"The stabilization effect of a strong HF electric field on the beam-plasma instability in a cylindrical warm plasma waveguide is discussed. A new mathematical technique \"separation method\" applied to the two-fluid plasma model to separate the equations, which describe the system, into two parts; time and space parts. Plasma electrons are considered to have a thermal velocity. It is shown that a HF electric field has no essential influence on dispersion characteristics of unstable surface waves excited in a warm plasma waveguide by a low-density electron beam. The region of instability only slightly narrowing and the growth rate decreases by a small parameter and this result has been reduced compared to cold plasma. Also, it is found that the plasma electrons have not affected the solution of the space part of the problem.","PeriodicalId":123517,"journal":{"name":"Proceedings of the Eighteenth National Radio Science Conference. NRSC'2001 (IEEE Cat. No.01EX462)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122209334","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
Speech compression using wavelet transform 基于小波变换的语音压缩
Proceedings of the Eighteenth National Radio Science Conference. NRSC'2001 (IEEE Cat. No.01EX462) Pub Date : 2001-03-27 DOI: 10.1109/NRSC.2001.929405
F. W. Zaki, H. Hashish, S. Behiry
{"title":"Speech compression using wavelet transform","authors":"F. W. Zaki, H. Hashish, S. Behiry","doi":"10.1109/NRSC.2001.929405","DOIUrl":"https://doi.org/10.1109/NRSC.2001.929405","url":null,"abstract":"A great deal of mathematical and engineering analysis depends on methods for representing a complex phenomenon in terms of elementary, well-understood phenomena. Recently wavelet theory has provided a new method for decomposing a function or signal. Wavelet transforms of real signals tend to create low-value coefficients at the finer scale. This property makes it possible to devise compression schemes that quantise the fine-scale coefficients more severely than coefficients at other scales. In this paper, two schemes for speech compression based on wavelet transform are introduced. In the first one, short time segments of speech samples are wavelet transformed and quantised using different types of quantisers. In the second scheme, a linear prediction is carried out using the autocorrelation method and tapped delay line transversal filter, then the prediction residual is wavelet transformed, quantised, and transmitted. A good quality speech reproduction is obtained at compression ratios of 50%-90.36%. The system may find its applications in cellular and satellite communications.","PeriodicalId":123517,"journal":{"name":"Proceedings of the Eighteenth National Radio Science Conference. NRSC'2001 (IEEE Cat. No.01EX462)","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134192647","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
Planar array synthesis with scattered inverted-element locations using neural networks 基于神经网络的散射反元位置平面阵列综合
Proceedings of the Eighteenth National Radio Science Conference. NRSC'2001 (IEEE Cat. No.01EX462) Pub Date : 2001-03-27 DOI: 10.1109/NRSC.2001.929166
H. Elkamchouchi, G.A. Saleh
{"title":"Planar array synthesis with scattered inverted-element locations using neural networks","authors":"H. Elkamchouchi, G.A. Saleh","doi":"10.1109/NRSC.2001.929166","DOIUrl":"https://doi.org/10.1109/NRSC.2001.929166","url":null,"abstract":"A new approach is proposed for the planar array synthesis problem. The method assumes the array elements to be scattered in a plane with each element having a brother element with the same excitation but at an inverted location. These assumptions allow the analogy between the array factor and the output of an artificial neural network (ANN) that is made to learn it. Thus, the parameters of the planar array can be extracted from the weights and biases of the trained ANN. Results of using the approach to synthesize uniformly spaced nonuniformly excited arrays and nonuniformly spaced nonuniformly excited arrays are shown and compared.","PeriodicalId":123517,"journal":{"name":"Proceedings of the Eighteenth National Radio Science Conference. NRSC'2001 (IEEE Cat. No.01EX462)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114068170","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
Six-port reflectometer realization using two microstrip three-section couplers 使用两个微带三段耦合器实现六端口反射计
Proceedings of the Eighteenth National Radio Science Conference. NRSC'2001 (IEEE Cat. No.01EX462) Pub Date : 2001-03-27 DOI: 10.1109/NRSC.2001.929158
A. Mohra
{"title":"Six-port reflectometer realization using two microstrip three-section couplers","authors":"A. Mohra","doi":"10.1109/NRSC.2001.929158","DOIUrl":"https://doi.org/10.1109/NRSC.2001.929158","url":null,"abstract":"The single-section couplers are narrow band devices, so in order to broaden the useful bandwidth, three-section couplers are used. In this paper a system of two of three-section couplers is used to construct a six-port reflectometer. The realized six-port reflectometer is calibrated and used to measure different unknown complex terminations. The results of the six-port reflectometer is found to be in good agreement with the measurements of the vector network analyzer (HP-8510C) with an error not exceeding 4% in magnitude and 4/spl deg/ in phase in the frequency range (2.4-4.4 GHz).","PeriodicalId":123517,"journal":{"name":"Proceedings of the Eighteenth National Radio Science Conference. NRSC'2001 (IEEE Cat. No.01EX462)","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115259425","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
首页 上一页 下一页 尾页
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整，为了账户安全，请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
请完成安全验证×
相关产品
×
本文献相关产品
联系我们：info@booksci.cn Book学术提供免费学术资源搜索服务，方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号：604180095
Book学术官方微信