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ITS'98 Proceedings. SBT/IEEE International Telecommunications Symposium (Cat. No.98EX202)最新文献

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Prosodic speech modifications using pitch-synchronous time-frequency interpolation 使用音高同步时频插值的韵律语音修改
ITS'98 Proceedings. SBT/IEEE International Telecommunications Symposium (Cat. No.98EX202) Pub Date : 1998-08-09 DOI: 10.1109/ITS.1998.713121
E.S. Morais, F. Violaro, P. Barbosa
{"title":"Prosodic speech modifications using pitch-synchronous time-frequency interpolation","authors":"E.S. Morais, F. Violaro, P. Barbosa","doi":"10.1109/ITS.1998.713121","DOIUrl":"https://doi.org/10.1109/ITS.1998.713121","url":null,"abstract":"This paper presents a method to apply time-frequency interpolation (TFI) to prosodic speech modifications. The basic concepts of representing the speech signal in the time-frequency domain are described. A system based on synchronous TFI is proposed, and application examples of this system to time and pitch scale modifications are presented. Informal subjective tests are performed. They highlight the superior quality of the proposed system in comparison with the time-domain pitch synchronous overlap and add (TD-PSOLA) technique of speech synthesis.","PeriodicalId":205350,"journal":{"name":"ITS'98 Proceedings. SBT/IEEE International Telecommunications Symposium (Cat. No.98EX202)","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126053045","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
Parallel architecture for high-speed Reed-Solomon codec 高速Reed-Solomon编解码器的并行架构
ITS'98 Proceedings. SBT/IEEE International Telecommunications Symposium (Cat. No.98EX202) Pub Date : 1998-08-09 DOI: 10.1109/ITS.1998.718439
T. Matsushima, T. Matsushima, S. Hirasawa
{"title":"Parallel architecture for high-speed Reed-Solomon codec","authors":"T. Matsushima, T. Matsushima, S. Hirasawa","doi":"10.1109/ITS.1998.718439","DOIUrl":"https://doi.org/10.1109/ITS.1998.718439","url":null,"abstract":"This paper presents a parallel architecture for a high-speed Reed-Solomon (RS) encoder and decoder (codec) LSI. Since the architecture allows H symbols to be processed in parallel the codec LSI achieves a data rate of mLH b/s. where m is the symbol size (m bits per symbol), L is the clock frequency of the circuit, and H is an arbitrary integer. As an example, we investigate hardware complexity, delay and critical path length for a (255.251) RS code. It is shown that both the hardware complexity and the delay for a parallel circuit is much less than that with the parallel operation of H conventional circuits. Although the only problem with, this parallel architecture is that the encoder's critical path length increases with H, the proposed architectures is more efficient than a setup using H conventional circuits for high data rate applications. It is also suggested that parallel RS codecs, which can keep up with optical transmission rates, i.e. several giga bits/sec. could be implemented on one LSI chip, using current CMOS technology.","PeriodicalId":205350,"journal":{"name":"ITS'98 Proceedings. SBT/IEEE International Telecommunications Symposium (Cat. No.98EX202)","volume":"887 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125471962","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
A new iterative method to solve a volume integral equation 求解体积积分方程的一种新的迭代方法
ITS'98 Proceedings. SBT/IEEE International Telecommunications Symposium (Cat. No.98EX202) Pub Date : 1998-08-09 DOI: 10.1109/ITS.1998.718427
S. A. de Carvalho, L. Mendes
{"title":"A new iterative method to solve a volume integral equation","authors":"S. A. de Carvalho, L. Mendes","doi":"10.1109/ITS.1998.718427","DOIUrl":"https://doi.org/10.1109/ITS.1998.718427","url":null,"abstract":"A new iterative method for solving a volume integral equation is developed. The method consists of the division of the domain into subdomains, every subdomain characterized by a moment matrix that determines the field induced by the excitation. The entire solution is built by interaction among the subdomains, with the incident field as the initial excitation.","PeriodicalId":205350,"journal":{"name":"ITS'98 Proceedings. SBT/IEEE International Telecommunications Symposium (Cat. No.98EX202)","volume":"114 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132013519","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
New unit-memory codes obtained by puncturing periodically time-varying convolutional codes 通过穿刺周期性时变卷积码获得新的单位记忆码
ITS'98 Proceedings. SBT/IEEE International Telecommunications Symposium (Cat. No.98EX202) Pub Date : 1998-08-09 DOI: 10.1109/ITS.1998.718451
B.F. Uchoa Filho, R. Palazzo, C. de Almeida, A. Said
{"title":"New unit-memory codes obtained by puncturing periodically time-varying convolutional codes","authors":"B.F. Uchoa Filho, R. Palazzo, C. de Almeida, A. Said","doi":"10.1109/ITS.1998.718451","DOIUrl":"https://doi.org/10.1109/ITS.1998.718451","url":null,"abstract":"New good high-rate punctured convolutional codes (PCC) are presented. While any previously known PCC was derived by puncturing a low-rate time-invariant mother code, the new PCC are shown to be derived by puncturing a periodically time-varying convolutional code (PTVCC) acting as the mother code. To find the new PCC, we first show that any PTVCC (hence, any PCC) is equivalent to a type of time-invariant convolutional code. Focusing on a fixed unit-memory (UM) code, we also show that under certain conditions there exists a PTVCC along with a puncturing pattern that is equivalent to that UM code. A combinatorial optimization algorithm is then used to search for the new good UM codes for which equivalent PCC do exist. We observe that the new PCC compare favorably to the previously known PCC in several respects.","PeriodicalId":205350,"journal":{"name":"ITS'98 Proceedings. SBT/IEEE International Telecommunications Symposium (Cat. No.98EX202)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132083839","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
Cell level performance approach for link dimensioning of ATM networks ATM网络链路维度的小区级性能方法
ITS'98 Proceedings. SBT/IEEE International Telecommunications Symposium (Cat. No.98EX202) Pub Date : 1998-08-09 DOI: 10.1109/ITS.1998.713115
J. de Oliveira, I. S. Bonatti, P. Peres, A. Budri
{"title":"Cell level performance approach for link dimensioning of ATM networks","authors":"J. de Oliveira, I. S. Bonatti, P. Peres, A. Budri","doi":"10.1109/ITS.1998.713115","DOIUrl":"https://doi.org/10.1109/ITS.1998.713115","url":null,"abstract":"ATM network dimensioning depends on the determination of the link capacity to ensure traffic demand meets a specific grade of service (cell loss probability, cell transfer delay and maximum delay variation). This paper proposes a new approach regarding the determination of the ATM link capacity. Starting from traffic and quality of service parameters and descriptors proposed by the ITU-T and ATM Forum, the best match of the effective bandwidth definitions is selected for each service class, using probabilistic models for connection cell loss and worst-case models for connection cell delay.","PeriodicalId":205350,"journal":{"name":"ITS'98 Proceedings. SBT/IEEE International Telecommunications Symposium (Cat. No.98EX202)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131301701","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 coded modulation scheme for a broadcast AWGN channel 广播AWGN信道的编码调制方案
ITS'98 Proceedings. SBT/IEEE International Telecommunications Symposium (Cat. No.98EX202) Pub Date : 1998-08-09 DOI: 10.1109/ITS.1998.718437
M. Pellenz, J. Portugheis
{"title":"A coded modulation scheme for a broadcast AWGN channel","authors":"M. Pellenz, J. Portugheis","doi":"10.1109/ITS.1998.718437","DOIUrl":"https://doi.org/10.1109/ITS.1998.718437","url":null,"abstract":"This paper proposes a coded modulation scheme for transmission of two classes of information on a broadcast AWGN channel. The scheme is based on multilevel coding with a nonstandard partition of a 32-QAM constellation. The QAM constellation consists of four groups of 8-PSK subconstellations instead of 8-QAM subconstellations. This results in a constellation with reduced peak-to-average power ratio. As component codes of the multilevel construction only one binary convolutional code and a punctured version of it are used. The nonstandard partition allows parallel decoding of the component codes in a multistage decoding algorithm. The error performance of the proposed scheme is obtained. In comparison with Wei's scheme with similar parameters, the proposed scheme achieves higher coding gains for the most important class at the cost of a small degradation in performance for the less important class. Although only results for a specific constellation are presented, the design principles can be easily extended to other QAM constellations.","PeriodicalId":205350,"journal":{"name":"ITS'98 Proceedings. SBT/IEEE International Telecommunications Symposium (Cat. No.98EX202)","volume":"112 11","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113969345","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: 5
Comparison of antenna array algorithms for CDMA mobile communications systems CDMA移动通信系统天线阵列算法的比较
ITS'98 Proceedings. SBT/IEEE International Telecommunications Symposium (Cat. No.98EX202) Pub Date : 1998-08-09 DOI: 10.1109/ITS.1998.713145
R. Carrasco
{"title":"Comparison of antenna array algorithms for CDMA mobile communications systems","authors":"R. Carrasco","doi":"10.1109/ITS.1998.713145","DOIUrl":"https://doi.org/10.1109/ITS.1998.713145","url":null,"abstract":"Summary form only given. Various linear and nonlinear algorithms for adaptive antenna arrays in code division multiple access (CDMA) mobile communication systems are investigated. The computer-simulated system model incorporates QPSK-CDMA modulation, demodulation, diversity channels and adaptive array structures. Diversity channels are time-varying and have frequency-selective fading characteristics. Simulation results show that the optimal technique in terms of performance and computational complexity is based on a recurrent neural network (RNN) structure.","PeriodicalId":205350,"journal":{"name":"ITS'98 Proceedings. SBT/IEEE International Telecommunications Symposium (Cat. No.98EX202)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121193393","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
Image coding by using eventually contractive discrete fractal transformations 图像编码采用最终压缩离散分形变换
ITS'98 Proceedings. SBT/IEEE International Telecommunications Symposium (Cat. No.98EX202) Pub Date : 1998-08-09 DOI: 10.1109/ITS.1998.718460
J.F.L. de Oliveira, G. Mendonça, R.J. Dias
{"title":"Image coding by using eventually contractive discrete fractal transformations","authors":"J.F.L. de Oliveira, G. Mendonça, R.J. Dias","doi":"10.1109/ITS.1998.718460","DOIUrl":"https://doi.org/10.1109/ITS.1998.718460","url":null,"abstract":"In the last few years, the discrete fractal transformation has been applied to image coding in order to obtain high compression rates. The coding scheme works by dividing an image into range blocks that are approximated, through a contractive fractal transformation, by low-pass-filtered versions of the domain blocks selected in the image itself. It is reported in Fisher (1994) that using eventually contractive fractal transformations one can improve the compressed image quality. However, no explanation is given to justify this fact. We address this issue by relating this improvement, which can reach 1 dB (PSNR), to the filtering process of the domain blocks.","PeriodicalId":205350,"journal":{"name":"ITS'98 Proceedings. SBT/IEEE International Telecommunications Symposium (Cat. No.98EX202)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116063631","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
An analytical method for assessing interference in an environment involving NGSO satellite networks 一种在涉及NGSO卫星网络的环境中评估干扰的分析方法
ITS'98 Proceedings. SBT/IEEE International Telecommunications Symposium (Cat. No.98EX202) Pub Date : 1998-08-09 DOI: 10.1109/ITS.1998.713082
J. Fortes, R. Sampaio-Neto
{"title":"An analytical method for assessing interference in an environment involving NGSO satellite networks","authors":"J. Fortes, R. Sampaio-Neto","doi":"10.1109/ITS.1998.713082","DOIUrl":"https://doi.org/10.1109/ITS.1998.713082","url":null,"abstract":"This paper presents an analytical approach to assessing interference involving nongeostationary (NGSO) satellite networks. The proposed method can be implemented through numerical techniques, and is intended to perform the analysis of interference sensitivity to system and network parameters without requiring lengthy computer simulation runs. It is based on the knowledge of the probability density function of the position of a single satellite placed in an orbit with an arbitrary inclination, which is derived in the paper. To illustrate the method, results for a simple example are presented and compared to those obtained via direct computer simulation. Although applied here to a simple situation, the proposed method is general and can be used in more complex situations involving two or more NGSO satellite networks, taking into account all satellites in each constellation.","PeriodicalId":205350,"journal":{"name":"ITS'98 Proceedings. SBT/IEEE International Telecommunications Symposium (Cat. No.98EX202)","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116509354","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: 5
Multistage decoding of block multidimensional M-PSK modulation codes 块多维M-PSK调制码的多级解码
ITS'98 Proceedings. SBT/IEEE International Telecommunications Symposium (Cat. No.98EX202) Pub Date : 1998-08-09 DOI: 10.1109/ITS.1998.718438
N.L. Guerrero, J. Portugheis
{"title":"Multistage decoding of block multidimensional M-PSK modulation codes","authors":"N.L. Guerrero, J. Portugheis","doi":"10.1109/ITS.1998.718438","DOIUrl":"https://doi.org/10.1109/ITS.1998.718438","url":null,"abstract":"A class of block multidimensional M-PSK modulation codes was proposed by Portugeis (1991) and some 8-PSK codes were constructed. In comparison with codes using two-dimensional modulation, the constructed codes showed better phase symmetry properties and lower first error coefficients with multistage decoding. However, the trade-off between performance and decoding complexity was not thoroughly investigated. This paper presents a performance comparison of multistage decoding schemes for the constructed codes on an AWGN channel. Upper bounds to block error probability (P/sub B/) for these schemes are obtained and their tightness confirmed by simulation. One of the schemes has a coding gain of 3.9 dB over uncoded 4-PSK at P/sub B/=10/sup -4/ and a gain of 0.3 dB over a two-dimensional 8-PSK code with similar parameters at the cost of an acceptable increase in decoding complexity.","PeriodicalId":205350,"journal":{"name":"ITS'98 Proceedings. SBT/IEEE International Telecommunications Symposium (Cat. No.98EX202)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128707883","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
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