{"title":"An application of the nonlinear stochastic estimation theory to the interference reduction in communication systems","authors":"P. Rapajic, H.O. Beca","doi":"10.1109/MELCON.1989.50077","DOIUrl":"https://doi.org/10.1109/MELCON.1989.50077","url":null,"abstract":"An application of the nonlinear stochastic estimation theory to the problem of interference reduction among communication systems is analyzed. A significant overlapping of the spectra of the desired and interfering signals is assumed. The solution obtained takes the form of an extended Kalman filter. For such a solution some a priori data are needed, e.g. spectra and modulation techniques of the signals involved. Only angle-modulated signals are considered. In the simplest case, a receiver is obtained that corresponds to the MAP (maximum a posteriori) receiver. By taking more terms of the approximate solution to the Riccati equation, a superior solution for the present receiver is obtained. Digital simulations of the theoretical solutions confirm the suitability of the proposed method.<<ETX>>","PeriodicalId":380214,"journal":{"name":"Proceedings. Electrotechnical Conference Integrating Research, Industry and Education in Energy and Communication Engineering',","volume":"23 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":"117128585","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}
{"title":"Conjugate gradient equalizers adaptation algorithm versus LMS algorithm","authors":"J. Tasic, P. Blaznik","doi":"10.1109/MELCON.1989.50017","DOIUrl":"https://doi.org/10.1109/MELCON.1989.50017","url":null,"abstract":"The LMS (least mean square) and conjugate-gradient window (CGW) algorithms are considered for use in digital equalizers. The equalizer with implementation of the CGW algorithm is shown to require more computation, but the convergence is faster and the equalizer can be used in worse conditions. The simulation results are encouraging. The implementation of the CGW method for multilevel quadrature modulation is noted.<<ETX>>","PeriodicalId":380214,"journal":{"name":"Proceedings. Electrotechnical Conference Integrating Research, Industry and Education in Energy and Communication Engineering',","volume":"17 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":"115385691","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}
R. Sacco, C. Di Giuliomaria, C. Capponi, T. D'Alessio, E. Zanette
{"title":"Improving spectral parameters estimation for non stationary biological signals by means of a real time adaptive system","authors":"R. Sacco, C. Di Giuliomaria, C. Capponi, T. D'Alessio, E. Zanette","doi":"10.1109/MELCON.1989.50019","DOIUrl":"https://doi.org/10.1109/MELCON.1989.50019","url":null,"abstract":"A novel spectrum analyzer is presented which implements a real-time fast Fourier transform up to a frequency of 40 kHz and uses the adaptive algorithm to estimate maximum frequency with a high immunity from noise. Starting with this adaptive filtering, the other spectral parameter can be easily estimated. The system has been evaluated both with simulated and real signals, showing performances uniformly better than those of commercially available systems. Some applications to Doppler and myoelectric signals are reported and discussed. Preliminary results show that this system can be profitably used when nonstationary signals are to be studied.<<ETX>>","PeriodicalId":380214,"journal":{"name":"Proceedings. Electrotechnical Conference Integrating Research, Industry and Education in Energy and Communication Engineering',","volume":"11 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":"125364764","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}
{"title":"On a contribution of artificial intelligence tools for curriculum development formalization","authors":"J. Soto, A. del Pozo","doi":"10.1109/MELCON.1989.50156","DOIUrl":"https://doi.org/10.1109/MELCON.1989.50156","url":null,"abstract":"The authors discuss the foundations, nature, and characteristics of a methodology that has been applied from a nonPiagetian viewpoint to redefine a curriculum development formalization proposal. The ways in which artificial intelligence and curriculum development interact is discussed. The curriculum model described is connected directly with university environments, and the experience of the School of Engineering of Bilbao is briefly reported.<<ETX>>","PeriodicalId":380214,"journal":{"name":"Proceedings. Electrotechnical Conference Integrating Research, Industry and Education in Energy and Communication Engineering',","volume":"9 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":"128366310","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}
J. Prat, S. Ruiz-Moreno, M. Soneira, M. Garcia-Sempere
{"title":"Detection and location of the gain variations in an optical repeater chain","authors":"J. Prat, S. Ruiz-Moreno, M. Soneira, M. Garcia-Sempere","doi":"10.1109/MELCON.1989.50104","DOIUrl":"https://doi.org/10.1109/MELCON.1989.50104","url":null,"abstract":"A method is proposed that allows the detection and location of the gain variations generated in any section of an all-optical link formed by a set of fiber and optical-amplifier (OA) sections. The proposed method is shown to be a powerful and simple solution for the supervisory system of a link with optical amplification. It is suggested that this method can facilitate the practical application of the OA in long-haul transmission systems. By computer simulation of the optical link and the supervisory system, the accuracy of the method has been shown. Different error sources, the quantum and receiver noise, the saturation of the OA, and the possibility of nonidentical sections were taken into account. This has led to the proposed configuration of the supervisory system that detects and locates failures of the optical link.<<ETX>>","PeriodicalId":380214,"journal":{"name":"Proceedings. Electrotechnical Conference Integrating Research, Industry and Education in Energy and Communication Engineering',","volume":"85 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":"127863298","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}
{"title":"Torque control of a synchronous motor with field using a state feedback","authors":"Maurice Fadel, B. D. Fornel","doi":"10.1109/MELCON.1989.50007","DOIUrl":"https://doi.org/10.1109/MELCON.1989.50007","url":null,"abstract":"It is noted that the introduction of microprocessors in a control loop allows the implementation of new control structures. On the basis of this idea, the authors propose modern regulation techniques for the control of the electromagnetic torque of a synchronous motor. From the state-space representation of systems, they propose the decomposition of the process dynamic into two time scales, in order to give a reduced-order action model of the device. This reduced state model will be the basis for the construction of a flux observer, with a structure simple enough to be implemented, in real time, in the control loop of the motor. A modal control system which allows the control of the transient-state evolution of state variables in the speed drive is developed.<<ETX>>","PeriodicalId":380214,"journal":{"name":"Proceedings. Electrotechnical Conference Integrating Research, Industry and Education in Energy and Communication Engineering',","volume":"17 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":"116999814","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}
J.P. Sucena Paiva, L. Barruncho, A. Vidigal, H. Oliveira
{"title":"Voltage/VAr control: optimization and knowledge oriented approach-a contribution to advanced EMS","authors":"J.P. Sucena Paiva, L. Barruncho, A. Vidigal, H. Oliveira","doi":"10.1109/MELCON.1989.50002","DOIUrl":"https://doi.org/10.1109/MELCON.1989.50002","url":null,"abstract":"The key points in the development of a cooperative project between a university (Instituto Superior Tecnico) and the national power system utility of Portugal, EDP, are presented. The project is concerned with reactive management/voltage control and follows an approach for integration into the problem-solving environment of a modern newly installed energy control center, knowledge-oriented assistance to decision making, and coordination of numerical modules for optimization. A structured set of complementary tasks is presented as indispensable to the success of an online product in this area. The evaluation of the characteristics and choice of different tools for the different cooperative modules, algorithmic and knowledge-based, their integration and interaction with the existing system, performance and consistency compatible with real-time requirements, and man-machine interface are some of the problems considered.<<ETX>>","PeriodicalId":380214,"journal":{"name":"Proceedings. Electrotechnical Conference Integrating Research, Industry and Education in Energy and Communication Engineering',","volume":"51 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":"117084348","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}
{"title":"Modelling and simulation of high-speed direct detectionoptical fibre communication systems","authors":"H. da Silva, J. O'Reilly","doi":"10.1109/MELCON.1989.50109","DOIUrl":"https://doi.org/10.1109/MELCON.1989.50109","url":null,"abstract":"A simulation strategy suitable for performance assessment of long-haul high-bit-rate direct-detection systems is presented. Particular consideration is given to the interaction with fiber dispersion of laser modulation phenomena such as frequency chirp and patterning which exhibit complex nonlinear data dependence. The nonlinear modulation response of the laser transmitter is taken into account by using pseudo-random data sequences to estimate the dispersion-induced performance degradation. The dependence of the modulation and dispersion-induced penalties on the extinction ratio of the laser emission is shown for the specific case of 4 Gb/s NRZ modulation and a total dispersion L*D=1 ns/nm. With this approach, the implications for system performance of the laser operating point, modulation format used, receiver filter bandwidth, and timing acquisition imperfections are investigated, and some performance limitations are indicated.<<ETX>>","PeriodicalId":380214,"journal":{"name":"Proceedings. Electrotechnical Conference Integrating Research, Industry and Education in Energy and Communication Engineering',","volume":"108 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":"121427661","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}
{"title":"A monolithic double balanced mixer using passive GaAs MESFETs","authors":"T. Narhi","doi":"10.1109/MELCON.1989.50050","DOIUrl":"https://doi.org/10.1109/MELCON.1989.50050","url":null,"abstract":"A monolithic double balanced mixer has been realized using 1- mu m GaAs technology. It utilizes the channel resistance of a MESFET operating in the linear region to produce a strong mixer with a high compression point and low intermodulation distortion. Conversion loss of 5.5 dB and an input third-order intercept point of 21 dBm have been measured.<<ETX>>","PeriodicalId":380214,"journal":{"name":"Proceedings. Electrotechnical Conference Integrating Research, Industry and Education in Energy and Communication Engineering',","volume":"83 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":"126295327","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}
{"title":"Using PROLOG for digital circuits simulation","authors":"T. Welzer, I. Rozman, J. Gyorkos","doi":"10.1109/MELCON.1989.50151","DOIUrl":"https://doi.org/10.1109/MELCON.1989.50151","url":null,"abstract":"The use of PROLOG for digital circuit simulation in the education process is discussed. It is noted that the curriculum of the University of Maribor gives electrical engineering students some basic knowledge of computer techniques and FORTRAN or Pascal. On this basis, PROLOG can be presented to the students in order to acquaint them with some fundamentals of this fifth-generation language. The students who have acquired basic knowledge of PROLOG are able to define digital circuits specification programs as well as other simple PROLOG rules. The experience that students gain makes them capable of understanding similar models of conventional engineering as well as the basic working of expert systems.<<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":"125464232","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}