Pub Date : 1989-04-11DOI: 10.1109/MELCON.1989.50022
M. Nasr
In an effort to reduce queuing delay and increase the number of channels in a given bandwidth, a multiple-user variable-rate hybrid constant factor incremental data modulator is presented. The proposed system has a statistical multiplexing scheme incorporated with a packet transmission concept. Only the speech is encoded, while the silence portions are transmitted in header bits of each packet generated by a packet assembler. Computer simulations have been performed for real speech. The results indicate that the new system yields a performance improvement of about 8 dB over the conventional (single-user) systems.<>
{"title":"A multiple user variable rate speech coding for packet transmission systems","authors":"M. Nasr","doi":"10.1109/MELCON.1989.50022","DOIUrl":"https://doi.org/10.1109/MELCON.1989.50022","url":null,"abstract":"In an effort to reduce queuing delay and increase the number of channels in a given bandwidth, a multiple-user variable-rate hybrid constant factor incremental data modulator is presented. The proposed system has a statistical multiplexing scheme incorporated with a packet transmission concept. Only the speech is encoded, while the silence portions are transmitted in header bits of each packet generated by a packet assembler. Computer simulations have been performed for real speech. The results indicate that the new system yields a performance improvement of about 8 dB over the conventional (single-user) systems.<<ETX>>","PeriodicalId":380214,"journal":{"name":"Proceedings. Electrotechnical Conference Integrating Research, Industry and Education in Energy and Communication Engineering',","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114094295","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}
Pub Date : 1989-04-11DOI: 10.1109/MELCON.1989.50105
J. Hernandez Marco, A. Martín Joven, L. Torner
A multilayer structure forming a single-mode integrated optical isolator is analyzed with special emphasis on the dimensional conditions to be fulfilled in order to match the device with single-mode optical fibers optically used in coherent communication systems. A magnetooptical layer is included just below the active one in order to improve the performance of the isolator. The fundamental mode behavior in the multilayer guide is investigated. The mode propagation in the guide in an external magnetic field with Faraday configuration is also studied, and it is shown that the performance of the device improves with higher specific Faraday rotation of the substrate.<>
{"title":"Single-mode isolator in integrated optics","authors":"J. Hernandez Marco, A. Martín Joven, L. Torner","doi":"10.1109/MELCON.1989.50105","DOIUrl":"https://doi.org/10.1109/MELCON.1989.50105","url":null,"abstract":"A multilayer structure forming a single-mode integrated optical isolator is analyzed with special emphasis on the dimensional conditions to be fulfilled in order to match the device with single-mode optical fibers optically used in coherent communication systems. A magnetooptical layer is included just below the active one in order to improve the performance of the isolator. The fundamental mode behavior in the multilayer guide is investigated. The mode propagation in the guide in an external magnetic field with Faraday configuration is also studied, and it is shown that the performance of the device improves with higher specific Faraday rotation of the substrate.<<ETX>>","PeriodicalId":380214,"journal":{"name":"Proceedings. Electrotechnical Conference Integrating Research, Industry and Education in Energy and Communication Engineering',","volume":"169 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116238895","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}
Pub Date : 1989-04-11DOI: 10.1109/MELCON.1989.50093
J. Olmos, F. Casadevall
The authors present a novel method for assessing the bit error probability in a QAM (quadrature amplitude modulation) system, taking into account thermal noise, multipath distortion, and phase jitter. System signature is calculated for a system without any specific protection against multipath and for an IF (intermediate frequency) equalized system. Minimum-phase as well as nonminimum-phase fading is considered. As a representative result, the system signatures are shown for P( epsilon )=10/sup -3/ in a 16 QAM system at 140 Mb/s.<>
{"title":"Performance of 16 and 64 QAM digital radio systems with multipath propagation and distortion induced phase jitter","authors":"J. Olmos, F. Casadevall","doi":"10.1109/MELCON.1989.50093","DOIUrl":"https://doi.org/10.1109/MELCON.1989.50093","url":null,"abstract":"The authors present a novel method for assessing the bit error probability in a QAM (quadrature amplitude modulation) system, taking into account thermal noise, multipath distortion, and phase jitter. System signature is calculated for a system without any specific protection against multipath and for an IF (intermediate frequency) equalized system. Minimum-phase as well as nonminimum-phase fading is considered. As a representative result, the system signatures are shown for P( epsilon )=10/sup -3/ in a 16 QAM system at 140 Mb/s.<<ETX>>","PeriodicalId":380214,"journal":{"name":"Proceedings. Electrotechnical Conference Integrating Research, Industry and Education in Energy and Communication Engineering',","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116329479","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}
Pub Date : 1989-04-11DOI: 10.1109/MELCON.1989.50121
B.M. Propovic
A novel construction method for the generation of complex sequences with ideal periodic autocorrelation function is presented. The construction is based on the application of the k-valued character operator to the q-ary linear shift register sequences. As a special case, for k=2 this method produces a large class of ternary sequences proposed previously by V.P. Ipatov (1980). Also, ternary sequences by J.A. Chang (1967) can be obtained as a special case for k=2 and q=3.<>
{"title":"New class of complex sequences with ideal autocorrelation","authors":"B.M. Propovic","doi":"10.1109/MELCON.1989.50121","DOIUrl":"https://doi.org/10.1109/MELCON.1989.50121","url":null,"abstract":"A novel construction method for the generation of complex sequences with ideal periodic autocorrelation function is presented. The construction is based on the application of the k-valued character operator to the q-ary linear shift register sequences. As a special case, for k=2 this method produces a large class of ternary sequences proposed previously by V.P. Ipatov (1980). Also, ternary sequences by J.A. Chang (1967) can be obtained as a special case for k=2 and q=3.<<ETX>>","PeriodicalId":380214,"journal":{"name":"Proceedings. Electrotechnical Conference Integrating Research, Industry and Education in Energy and Communication Engineering',","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114618945","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}
Pub Date : 1989-04-11DOI: 10.1109/MELCON.1989.50026
J. Junqua, H. Wakita
The authors describe a novel automatic segmentation system based on perceptual cues, spectral dynamics, and various sources of knowledge: heuristic, phonetic, and suprasegmental. Because no reference units are used, the method can be directly applied to speech recognition. The passage from one application to another is facilitated by the modularity and openness given by the backboard model. This method has several advantages over other segmentation methods presented in the literature: it is based on an open and modular architecture; the smooth spectrum yielded by the perceptually based linear prediction analysis limits spurious segments; the algorithm which determines the transitions uses no threshold and thus is speaker independent; the system does not require reference units; and the introduction of phonetic knowledge deals mostly with the difficult cases.<>
{"title":"A knowledge based approach for automatic labeling of a large speech database","authors":"J. Junqua, H. Wakita","doi":"10.1109/MELCON.1989.50026","DOIUrl":"https://doi.org/10.1109/MELCON.1989.50026","url":null,"abstract":"The authors describe a novel automatic segmentation system based on perceptual cues, spectral dynamics, and various sources of knowledge: heuristic, phonetic, and suprasegmental. Because no reference units are used, the method can be directly applied to speech recognition. The passage from one application to another is facilitated by the modularity and openness given by the backboard model. This method has several advantages over other segmentation methods presented in the literature: it is based on an open and modular architecture; the smooth spectrum yielded by the perceptually based linear prediction analysis limits spurious segments; the algorithm which determines the transitions uses no threshold and thus is speaker independent; the system does not require reference units; and the introduction of phonetic knowledge deals mostly with the difficult cases.<<ETX>>","PeriodicalId":380214,"journal":{"name":"Proceedings. Electrotechnical Conference Integrating Research, Industry and Education in Energy and Communication Engineering',","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128686773","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}
Pub Date : 1989-04-11DOI: 10.1109/MELCON.1989.50020
M. Fratti, G. Parladori
The regular pulse excitation technique for speech coding at low bit rates provides good speech quality but involves a heavy computational effort. A novel method of reduced complexity is described which permits an efficient implementation on on a commercial DSP (digital signal processor) in terms of computation time and code compactness. The algorithm uses vector quantization for a vocal tract all-pole model. A complete implementation of an 8 kb/s codec working in full-duplex mode is performed on the Motorola mathematical mu P DSP56000. According to many informal listening tests, the speech quality at 8-kb/s is very close to that achieved at 64 kb/s using standard pulse-code modulation.<>
{"title":"Implementation of a RPE codec on a commercial DSP","authors":"M. Fratti, G. Parladori","doi":"10.1109/MELCON.1989.50020","DOIUrl":"https://doi.org/10.1109/MELCON.1989.50020","url":null,"abstract":"The regular pulse excitation technique for speech coding at low bit rates provides good speech quality but involves a heavy computational effort. A novel method of reduced complexity is described which permits an efficient implementation on on a commercial DSP (digital signal processor) in terms of computation time and code compactness. The algorithm uses vector quantization for a vocal tract all-pole model. A complete implementation of an 8 kb/s codec working in full-duplex mode is performed on the Motorola mathematical mu P DSP56000. According to many informal listening tests, the speech quality at 8-kb/s is very close to that achieved at 64 kb/s using standard pulse-code modulation.<<ETX>>","PeriodicalId":380214,"journal":{"name":"Proceedings. Electrotechnical Conference Integrating Research, Industry and Education in Energy and Communication Engineering',","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123887762","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}
Pub Date : 1989-04-11DOI: 10.1109/MELCON.1989.50072
G. Stassinopoulos, J. Tsiligaridis
The authors analyze a typical multiplexer setup where the interplay between packet loss and delay is vividly illustrated. Arrival statistics are realistically contrasted for real-time (voice) and nonreal-time (data) packets. A multiplexer of real- and nonreal-time data is presented; it is considered as a generic network element appearing either within a user integrated service terminal or within a more elaborate user premises network accessing a packet switched integrated broadband communication facility. Markov analysis is performed for an asynchronous transfer mode (ATM) environment. Numerical results are presented.<>
{"title":"Multiplexing in the ATM environment","authors":"G. Stassinopoulos, J. Tsiligaridis","doi":"10.1109/MELCON.1989.50072","DOIUrl":"https://doi.org/10.1109/MELCON.1989.50072","url":null,"abstract":"The authors analyze a typical multiplexer setup where the interplay between packet loss and delay is vividly illustrated. Arrival statistics are realistically contrasted for real-time (voice) and nonreal-time (data) packets. A multiplexer of real- and nonreal-time data is presented; it is considered as a generic network element appearing either within a user integrated service terminal or within a more elaborate user premises network accessing a packet switched integrated broadband communication facility. Markov analysis is performed for an asynchronous transfer mode (ATM) environment. Numerical results are presented.<<ETX>>","PeriodicalId":380214,"journal":{"name":"Proceedings. Electrotechnical Conference Integrating Research, Industry and Education in Energy and Communication Engineering',","volume":"382 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125870225","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}
Pub Date : 1989-04-11DOI: 10.1109/MELCON.1989.49968
F. Carassa
Wideband communication (WC) is considered with reference to the general architecture of the public communication network. Two aspects of WC are discussed: wideband transmission within the network (linked to the traffic intensity to be dealt with) and wideband communication in the user access area (linked to the introduction of wideband services). In regard to the first aspect, the evolution of cable transmission (copper and optical fibers), radio relays, and satellite systems is considered: the main limitations on the transmission capacity are discussed with particular emphasis on transmission capacity per carrier. In regard to the second aspect, the possible wideband services are reviewed as requested by (or offered to) the business user and domestic users. Again, the possibility of using cable, radio, or satellite to reach the user is examined. WC within local area networks is discussed.<>
{"title":"Wideband communication systems","authors":"F. Carassa","doi":"10.1109/MELCON.1989.49968","DOIUrl":"https://doi.org/10.1109/MELCON.1989.49968","url":null,"abstract":"Wideband communication (WC) is considered with reference to the general architecture of the public communication network. Two aspects of WC are discussed: wideband transmission within the network (linked to the traffic intensity to be dealt with) and wideband communication in the user access area (linked to the introduction of wideband services). In regard to the first aspect, the evolution of cable transmission (copper and optical fibers), radio relays, and satellite systems is considered: the main limitations on the transmission capacity are discussed with particular emphasis on transmission capacity per carrier. In regard to the second aspect, the possible wideband services are reviewed as requested by (or offered to) the business user and domestic users. Again, the possibility of using cable, radio, or satellite to reach the user is examined. WC within local area networks is discussed.<<ETX>>","PeriodicalId":380214,"journal":{"name":"Proceedings. Electrotechnical Conference Integrating Research, Industry and Education in Energy and Communication Engineering',","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129987365","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}
Pub Date : 1989-04-11DOI: 10.1109/MELCON.1989.50056
L. Alparone, G. Benelli, V. Cappellini
Digital techniques for image processing and automatic classification in remote-sensing applications are described. Some digital filters suitable for radar noise reduction are reviewed. A novel filtering algorithm for multiplicative noise rejection is then proposed. Some algorithms using the maximum-likelihood decision rule or the Euclidean distance are applied to preprocessed images for an automatic discrimination of agricultural crops. Microwave images obtained by means of synthetic aperture radars and collected during the European SAR 580 campaign are used to evaluate the performance of the filtering algorithms. Both single-band and two-band classification with a correct classification probability of over 95% were obtained.<>
{"title":"Noise-reduction algorithms for digital radar images and classification of remote sensed agricultural SAR images","authors":"L. Alparone, G. Benelli, V. Cappellini","doi":"10.1109/MELCON.1989.50056","DOIUrl":"https://doi.org/10.1109/MELCON.1989.50056","url":null,"abstract":"Digital techniques for image processing and automatic classification in remote-sensing applications are described. Some digital filters suitable for radar noise reduction are reviewed. A novel filtering algorithm for multiplicative noise rejection is then proposed. Some algorithms using the maximum-likelihood decision rule or the Euclidean distance are applied to preprocessed images for an automatic discrimination of agricultural crops. Microwave images obtained by means of synthetic aperture radars and collected during the European SAR 580 campaign are used to evaluate the performance of the filtering algorithms. Both single-band and two-band classification with a correct classification probability of over 95% were obtained.<<ETX>>","PeriodicalId":380214,"journal":{"name":"Proceedings. Electrotechnical Conference Integrating Research, Industry and Education in Energy and Communication Engineering',","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117273648","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}
Pub Date : 1989-04-11DOI: 10.1109/MELCON.1989.50082
J. I. Solana, A. Santos, J.C. Lopez, C. López
A module generator that can customize adders, adder-subtracters, and shift registers is presented. It offers the user several design options and estimates the area and delays of the circuit to the obtained. Its output is the full layout of the circuit, and it can be integrated with other tools to obtain an automatic design environment. An estimate of the area and speed of the circuit is given so that the user may select the best solution among the different structures proposed.<>
{"title":"CMOS adder and shift register layout generators","authors":"J. I. Solana, A. Santos, J.C. Lopez, C. López","doi":"10.1109/MELCON.1989.50082","DOIUrl":"https://doi.org/10.1109/MELCON.1989.50082","url":null,"abstract":"A module generator that can customize adders, adder-subtracters, and shift registers is presented. It offers the user several design options and estimates the area and delays of the circuit to the obtained. Its output is the full layout of the circuit, and it can be integrated with other tools to obtain an automatic design environment. An estimate of the area and speed of the circuit is given so that the user may select the best solution among the different structures proposed.<<ETX>>","PeriodicalId":380214,"journal":{"name":"Proceedings. Electrotechnical Conference Integrating Research, Industry and Education in Energy and Communication Engineering',","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124471117","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}
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