Anais do 2002 International Telecommunications Symposium最新文献

The last mile problem solution using free space optical transmission broadband 最后一英里问题的解决采用自由空间光传输宽带

Anais do 2002 International Telecommunications Symposium Pub Date : 2015-04-12 DOI: 10.14209/its.2002.745

G. A. Stephens, S. Flórez

引用次数: 0

Mean-Squared Analysis of the Partial-Update NLMS Algorithm 部分更新NLMS算法的均方分析

Anais do 2002 International Telecommunications Symposium Pub Date : 2003-04-30 DOI: 10.14209/JCIS.2003.9

S. Werner, M. Campos, P. Diniz

引用次数: 7

End to end IP QoS assurance using policy based multi-agent SLA management systems 使用基于策略的多代理SLA管理系统实现端到端IP QoS保证

Anais do 2002 International Telecommunications Symposium Pub Date : 2003-04-30 DOI: 10.14209/JCIS.2003.3

M. Fonseca, N. Agoulmine

{"title":"End to end IP QoS assurance using policy based multi-agent SLA management systems","authors":"M. Fonseca, N. Agoulmine","doi":"10.14209/JCIS.2003.3","DOIUrl":"https://doi.org/10.14209/JCIS.2003.3","url":null,"abstract":"The development of Internet as well as overall communication technologies has created a very competitive communication market. In fact, there is no doubt that in the near future, every company and perhaps every person in the world will have an physical or wireless Internet access via an ISP (Internet Service Provider). Thus, the Internet became a very complex global network which represents an opportunity to provide worldwide value-added services requiring a certain level of quality of service (QoS) such as QoS-VPN (Virtual Private Network), VoD (Video On Demand). telelearning, e-Cornmerce, etc. Thus, we propose in this work to extend this approach in order to integrate new mechanisms that will allow customers to request end-to-end services. This assurance covers the QoS as well as associated parameters such as cost. The proposed solution introduces interoperability mechanisms between ISP policy based management systems and uses mobile agents to facilitate the negotiation between domains. The agent negotiation process is constrained by a set of predefined policies in order to limit the boundaries of the SLA parameters such as the cost. QoS, etc.","PeriodicalId":310988,"journal":{"name":"Anais do 2002 International Telecommunications Symposium","volume":"35 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122600342","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

A Family of Wavelets and a New Orthogonal Multiresolution Analysis Based on the Nyquist Criterion 基于奈奎斯特准则的一组小波和一种新的正交多分辨率分析

Anais do 2002 International Telecommunications Symposium Pub Date : 2003-04-30 DOI: 10.14209/jcis.2003.8

Hélio M. de Oliveira, L. R. Soares, T. Falk

引用次数: 11

VTLN Through Frequency Warping Based on Pitch 基于基音的虚拟磁带机频率翘曲

Anais do 2002 International Telecommunications Symposium Pub Date : 2003-04-30 DOI: 10.14209/JCIS.2003.10

C. Lopes, F. Perdigão

{"title":"VTLN Through Frequency Warping Based on Pitch","authors":"C. Lopes, F. Perdigão","doi":"10.14209/JCIS.2003.10","DOIUrl":"https://doi.org/10.14209/JCIS.2003.10","url":null,"abstract":"This article describes a Vocal Tract Length Nor malization (VTLN) procedure through frequency warping based on pitch estimates. This procedure aims to reduce the inter-speaker variability of speech signals in order to obtain a robust automatic speech recognition system. Two additional methods are also described: one for reducing the environment variability and another for compensating the coarticulation effects on connected word pronunciation. En vironment variability is compensated by explicitly modeling some frequent noise phenomena. Coarticulation phenomena compensation reduces speech signal variability by modeling events that result from coarticulation between adjacent mod els. Inter-speaker variability removal is performed by a traditional speaker normalization method, which consists in expanding or compressing the Mel filterbank bandwidths, in order to normalize the Vocal Tract Length (VTL) of each speaker. Most of the existing methods for VTL estimation are based on formant estimation, but the difficulty of formant estimation is a known performance limitation. The proposed method over comes such a problem since it estimates the warping factor through pitch. The recognition results, obtained for a tele phone digit recognition task (with phones and sub words as units), prove that this procedure leads to similar improve ments to those obtained with traditional methods based on formant estimates, actually outperforming them in some sit uations.","PeriodicalId":310988,"journal":{"name":"Anais do 2002 International Telecommunications Symposium","volume":"137 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124599127","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: 4

Turbo Coding for 4G Systems: Design Issues and Solutions 4G系统的Turbo编码:设计问题和解决方案

Anais do 2002 International Telecommunications Symposium Pub Date : 2003-04-30 DOI: 10.14209/JCIS.2003.5

A. Giulietti, M. Strum, B. Bougard, L. Perre

引用次数: 1

Space-Time Convolutional Codes Over GF(p) for the Quasi-Static, Flat Rayleigh Fading Channel 准静态平坦瑞利衰落信道GF(p)上的空时卷积码

Anais do 2002 International Telecommunications Symposium Pub Date : 2003-04-30 DOI: 10.14209/JCIS.2003.7

M. Noronha-Neto, R. Souza, B. Uchôa-Filho

{"title":"Space-Time Convolutional Codes Over GF(p) for the Quasi-Static, Flat Rayleigh Fading Channel","authors":"M. Noronha-Neto, R. Souza, B. Uchôa-Filho","doi":"10.14209/JCIS.2003.7","DOIUrl":"https://doi.org/10.14209/JCIS.2003.7","url":null,"abstract":"In this paper, we consider a space-time coded system consisting of a rate R = 1/ n linear convolutional encoder over GF( p ), p a prime, followed by n mappers from GF( p ) into a p -ary signal constellation, and by a transmitter with n transmit antennas. At each time, the n p -ary coded symbols are transmitted simultaneously from the n antennas. The convolutional codes are designed to provide the best error performance in the quasi-static, flat Rayleigh fading channel, according to the rank and the determinant criteria derived by Tarokh et al. A spectral efficiency of log 2 ( p ) b/s/Hz is achieved. Simple conditions on the generator matrices of a rate R = 1/2 convolutional code are given so that maximum diversity advantage is guaranteed. The linear structure of these convolutional codes reduces significantly the computer search effort with respect to the determinant criterion. In this regard, some properties of reciprocal STC's are derived. New space-time codes with two transmit antennas are presented for the 5-PSK and 7-PSK modulations, with spectral efficiencies 2.32 and 2.81 b/s/Hz, respectively. Simulation results in the form of frame error rate versus signal-to-noise ratio are reported for these codes, showing agreement with the theoretical results.","PeriodicalId":310988,"journal":{"name":"Anais do 2002 International Telecommunications Symposium","volume":"3 Suppl N 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133326681","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

Blind Source Separation and Channel Identification: Exploiting 2nd Order Statistics in Bayesian Frameworks 盲源分离和信道识别:利用贝叶斯框架中的二阶统计量

Anais do 2002 International Telecommunications Symposium Pub Date : 2003-04-30 DOI: 10.14209/JCIS.2003.11

P. Lopes, J. Xavier, V. Barroso

{"title":"Blind Source Separation and Channel Identification: Exploiting 2nd Order Statistics in Bayesian Frameworks","authors":"P. Lopes, J. Xavier, V. Barroso","doi":"10.14209/JCIS.2003.11","DOIUrl":"https://doi.org/10.14209/JCIS.2003.11","url":null,"abstract":"We study how 2nd order statistics (SOS) can be exploited in two signal processing problems, blind separation of binary sources and trained-based multi-user channel iden tification, in a Bayesian context where a prior on the mixing channel matrix is available. It is well known that the SOS of the received data permit to resolve the unknown mixing matrix, up to an orthogonal factor. In a Bayesian framework, this residual orthogonal mixing matrix becomes a random ob ject in its own right, with an associated distribution over the group of orthogonal matrices. This distribution is induced by the prior on the mixing matrix, and must be known for opti mum statistical processing. Ve rely on a previous theoretical work to provide these answers, and discuss applications for this induced probability density function (pdf) over the or thogonal group, in the two aforementioned signal processing problems. Preliminary results, obtained through computer simulations, demonstrate the effectiveness of incorporating this induced distribution associated with the residual orthog onal matrix into the design of several estimators.","PeriodicalId":310988,"journal":{"name":"Anais do 2002 International Telecommunications Symposium","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116609241","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

Acousto-Optic Tunable Filter (AOTF) with Increasing Nonlinearity and Loss 非线性和损耗增大的声光可调谐滤波器(AOTF)

Anais do 2002 International Telecommunications Symposium Pub Date : 2002-07-15 DOI: 10.1016/S0030-4018(02)01599-7

C. Sobrinho, J. Lima, E. F. Almeida, A. Sombra

引用次数: 12

On the minimum redundancy of homophonic coding 谐音编码的最小冗余

Anais do 2002 International Telecommunications Symposium Pub Date : 1900-01-01 DOI: 10.14209/its.2002.309

Valdemar C. da Rocha Jr.

引用次数: 0