Pub Date : 2001-07-04DOI: 10.1109/EURCON.2001.938167
I. Cheng, A. Basu, Yibo Zhang, S. Tripathi
Traditionally, multimedia delivery on the Internet has concentrated on providing a single service quality, "best effort", where all types of media are given the same level of importance in a network. Only recently has there been an emphasis on monitoring bandwidth in a network, and adjusting service quality depending on the current bandwidth. One important aspect on which little research has been done is: "how can users specify the requirements and priorities by which multimedia quality should be adjusted given bandwidth limitations"? We design a quality of service (QoS) specification strategy and delivery criteria using adaptive bandwidth monitoring that best fits the specifications to the available resources. In order to provide QoS-based delivery a prioritization method has been designed to order information according to the preferences of a user. Java applets and CGI programming tools are used to provide an interactive Web retrieval environment. At present, JPEG quality, resolution and delay are used as parameters to determine the QoS. We are extending the work to include video delivery and distributed implementation with QoS in the future.
{"title":"QoS specification and adaptive bandwidth monitoring for multimedia delivery","authors":"I. Cheng, A. Basu, Yibo Zhang, S. Tripathi","doi":"10.1109/EURCON.2001.938167","DOIUrl":"https://doi.org/10.1109/EURCON.2001.938167","url":null,"abstract":"Traditionally, multimedia delivery on the Internet has concentrated on providing a single service quality, \"best effort\", where all types of media are given the same level of importance in a network. Only recently has there been an emphasis on monitoring bandwidth in a network, and adjusting service quality depending on the current bandwidth. One important aspect on which little research has been done is: \"how can users specify the requirements and priorities by which multimedia quality should be adjusted given bandwidth limitations\"? We design a quality of service (QoS) specification strategy and delivery criteria using adaptive bandwidth monitoring that best fits the specifications to the available resources. In order to provide QoS-based delivery a prioritization method has been designed to order information according to the preferences of a user. Java applets and CGI programming tools are used to provide an interactive Web retrieval environment. At present, JPEG quality, resolution and delay are used as parameters to determine the QoS. We are extending the work to include video delivery and distributed implementation with QoS in the future.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127084959","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 : 2001-07-04DOI: 10.1109/EURCON.2001.938142
M. Dadić
Ghosts are time delayed, attenuated and distorted versions of the intended television signal. This paper treats the influence of the channel transfer function on performance of an adaptive inverse modeling method, namely the least mean squares (LMS) algorithm. The zeros in the channel transfer function correspond to poles in the inverse model. With these poles inside or outside the unit circle on the z-plane, accurate enough modeling can be achieved with left-handed and right-handed sequences, using finite impulse response (FIR) filters, large enough and modeling delay. For non-repeated poles, the level of residual ghosts is greater, but line-by-line processing can make them smaller and their level decreases when the number of taps is increased. Repeated poles cause the largest magnitudes of residual ghosts, and they cannot be suppressed more than a level even with an increased number of taps.
{"title":"Influence of channel transfer function on LMS algorithm based nonrecursive deghosting in analog TV","authors":"M. Dadić","doi":"10.1109/EURCON.2001.938142","DOIUrl":"https://doi.org/10.1109/EURCON.2001.938142","url":null,"abstract":"Ghosts are time delayed, attenuated and distorted versions of the intended television signal. This paper treats the influence of the channel transfer function on performance of an adaptive inverse modeling method, namely the least mean squares (LMS) algorithm. The zeros in the channel transfer function correspond to poles in the inverse model. With these poles inside or outside the unit circle on the z-plane, accurate enough modeling can be achieved with left-handed and right-handed sequences, using finite impulse response (FIR) filters, large enough and modeling delay. For non-repeated poles, the level of residual ghosts is greater, but line-by-line processing can make them smaller and their level decreases when the number of taps is increased. Repeated poles cause the largest magnitudes of residual ghosts, and they cannot be suppressed more than a level even with an increased number of taps.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124552817","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 : 2001-07-04DOI: 10.1109/EURCON.2001.937750
M. Munster, L. Hanzo
OFDM transmission is known to be sensitive against carrier frequency offsets, as well as against the channel impulse response (CIR) variations incurred during an OFDM symbol period. Both of these phenomena lead to inter-subcarrier interference (ICI). Here, we concentrate on the latter phenomenon. ICI can be considered as an additional noise contribution, which linearly depends on the signal power, and thus it potentially limits the achievable BER at relatively high SNRs. In this contribution, we propose a second-order time-domain CIR tap variation estimator, which relies on both the received signal as well as on tentative symbol decisions. Our simulation results, obtained in the context of a system employing decision-directed channel-prediction, demonstrate that, with the aid of the proposed algorithm, ICI cancellation can be performed even in high Doppler frequency channel scenarios. This is achieved without inserting additional time-domain pilot symbols.
{"title":"Second-order channel parameter estimation assisted cancellation of channel variation-induced inter-subcarrier interference in OFDM systems","authors":"M. Munster, L. Hanzo","doi":"10.1109/EURCON.2001.937750","DOIUrl":"https://doi.org/10.1109/EURCON.2001.937750","url":null,"abstract":"OFDM transmission is known to be sensitive against carrier frequency offsets, as well as against the channel impulse response (CIR) variations incurred during an OFDM symbol period. Both of these phenomena lead to inter-subcarrier interference (ICI). Here, we concentrate on the latter phenomenon. ICI can be considered as an additional noise contribution, which linearly depends on the signal power, and thus it potentially limits the achievable BER at relatively high SNRs. In this contribution, we propose a second-order time-domain CIR tap variation estimator, which relies on both the received signal as well as on tentative symbol decisions. Our simulation results, obtained in the context of a system employing decision-directed channel-prediction, demonstrate that, with the aid of the proposed algorithm, ICI cancellation can be performed even in high Doppler frequency channel scenarios. This is achieved without inserting additional time-domain pilot symbols.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"217 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124572671","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 : 2001-07-04DOI: 10.1109/EURCON.2001.938126
A. Zejak, I. Simic, B. Zrnic
The ambiguity function of chirp radar is shaped by compression filter design. The proposed optimization procedure for compression filter synthesis takes into account minimum loss in resolution and maximum reduction of sidelobes in the preferred Doppler range. This algorithm can be applied in high-resolution radar and sonar design.
{"title":"Chirp radar ambiguity function shaping","authors":"A. Zejak, I. Simic, B. Zrnic","doi":"10.1109/EURCON.2001.938126","DOIUrl":"https://doi.org/10.1109/EURCON.2001.938126","url":null,"abstract":"The ambiguity function of chirp radar is shaped by compression filter design. The proposed optimization procedure for compression filter synthesis takes into account minimum loss in resolution and maximum reduction of sidelobes in the preferred Doppler range. This algorithm can be applied in high-resolution radar and sonar design.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"109 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132334702","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 : 2001-07-04DOI: 10.1109/EURCON.2001.938159
R. Róka
This paper introduces a proposal for the utilization of VMSK modulation at the signal transport by means of xDSL technologies. First, the basic characteristics of the MSK and VMSK modulations are presented. Then we present a part dedicated to the mathematical analysis of the VMSK modulation. In the final part, we compare the QAM and VMSK modulation techniques and discuss the advantages of the VMSK and the possibilities for its utilization for high-speed transmission on metallic lines.
{"title":"The utilization of the VMSK modulation at the signal transport by means of xDSL technologies","authors":"R. Róka","doi":"10.1109/EURCON.2001.938159","DOIUrl":"https://doi.org/10.1109/EURCON.2001.938159","url":null,"abstract":"This paper introduces a proposal for the utilization of VMSK modulation at the signal transport by means of xDSL technologies. First, the basic characteristics of the MSK and VMSK modulations are presented. Then we present a part dedicated to the mathematical analysis of the VMSK modulation. In the final part, we compare the QAM and VMSK modulation techniques and discuss the advantages of the VMSK and the possibilities for its utilization for high-speed transmission on metallic lines.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133856690","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 : 2001-07-04DOI: 10.1109/EURCON.2001.937758
L. Hebbes, R. Malyan, P. Ball
Turbo codes are computationally intensive, but outperform many other channel coding schemes. This paper addresses the computational requirements of turbo codes and how these affect the performance of the coding scheme. Some pointers are given as to how to design codes that both perform well and have a reduced delay. Selection between codes with the same delay can be made based on performance. A formula is also presented that allows the prediction of the delay based on the computational complexities of a particular turbo code.
{"title":"Computational complexities and the relative performance of turbo codes","authors":"L. Hebbes, R. Malyan, P. Ball","doi":"10.1109/EURCON.2001.937758","DOIUrl":"https://doi.org/10.1109/EURCON.2001.937758","url":null,"abstract":"Turbo codes are computationally intensive, but outperform many other channel coding schemes. This paper addresses the computational requirements of turbo codes and how these affect the performance of the coding scheme. Some pointers are given as to how to design codes that both perform well and have a reduced delay. Selection between codes with the same delay can be made based on performance. A formula is also presented that allows the prediction of the delay based on the computational complexities of a particular turbo code.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117313199","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 : 2001-07-04DOI: 10.1109/EURCON.2001.937753
M. Boyle, A. Fagan
The use of a linear equaliser to shorten the impulse response of a channel to a shorter desired impulse response (DIR) prior to a Viterbi algorithm (VA) detection of the data is a well-known technique. It has been shown that, for dynamic channels, it is beneficial to operate a number of equalisers in parallel, each targeted on a different DIR. Each equaliser is followed by an individual VA. A simple decision rule is used to select which of the VA outputs is presented as the actual decision. We refer to this strategy as switched DIR equalisation. A degenerate mode is occasionally observed in the operation of this system that causes the equalisers to become severely misadjusted. The mean squared error becomes small but the bit error rate becomes very large. The system can not spontaneously recover from this situation. This paper reviews the switched DIR equalisation system, explains the mechanism underlying the degeneracy and proposes a method to avoid it. Simulation results are presented which verify the efficacy of the method.
{"title":"Switched Viterbi equalisation of dynamic channels and a degenerative error mode","authors":"M. Boyle, A. Fagan","doi":"10.1109/EURCON.2001.937753","DOIUrl":"https://doi.org/10.1109/EURCON.2001.937753","url":null,"abstract":"The use of a linear equaliser to shorten the impulse response of a channel to a shorter desired impulse response (DIR) prior to a Viterbi algorithm (VA) detection of the data is a well-known technique. It has been shown that, for dynamic channels, it is beneficial to operate a number of equalisers in parallel, each targeted on a different DIR. Each equaliser is followed by an individual VA. A simple decision rule is used to select which of the VA outputs is presented as the actual decision. We refer to this strategy as switched DIR equalisation. A degenerate mode is occasionally observed in the operation of this system that causes the equalisers to become severely misadjusted. The mean squared error becomes small but the bit error rate becomes very large. The system can not spontaneously recover from this situation. This paper reviews the switched DIR equalisation system, explains the mechanism underlying the degeneracy and proposes a method to avoid it. Simulation results are presented which verify the efficacy of the method.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127494017","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 : 2001-07-04DOI: 10.1109/EURCON.2001.938129
B. Kotnik, T. Rotovnik, Z. Kacic, B. Horvat, B. Horvat, I. Kramberger
The personal navigator presents a multimodal communication device. To its user it enables visual, tactile and voice communication. Visual and tactile communication between the user and the navigator runs over a graphical LCD display with touch-panel, which in that way serves as an input and output device. Through GSM data communication the personal navigator is connected to a navigation server, which runs on a personal computer and is also a constituent part of the whole personal navigator system. The personal navigator has built-in support for a digital signal processor by which the automatic speech synthesis and recognition are performed. The momentary scheme of the personal navigator enables a wide palette of applications like tourist guide functions (informing the user about his position, presenting tourist sites and guiding), information functions (giving daily news, Internet browser) and communication device (notebook SMS messages, E-mail).
{"title":"The design of mobile multimodal communication device - personal navigator","authors":"B. Kotnik, T. Rotovnik, Z. Kacic, B. Horvat, B. Horvat, I. Kramberger","doi":"10.1109/EURCON.2001.938129","DOIUrl":"https://doi.org/10.1109/EURCON.2001.938129","url":null,"abstract":"The personal navigator presents a multimodal communication device. To its user it enables visual, tactile and voice communication. Visual and tactile communication between the user and the navigator runs over a graphical LCD display with touch-panel, which in that way serves as an input and output device. Through GSM data communication the personal navigator is connected to a navigation server, which runs on a personal computer and is also a constituent part of the whole personal navigator system. The personal navigator has built-in support for a digital signal processor by which the automatic speech synthesis and recognition are performed. The momentary scheme of the personal navigator enables a wide palette of applications like tourist guide functions (informing the user about his position, presenting tourist sites and guiding), information functions (giving daily news, Internet browser) and communication device (notebook SMS messages, E-mail).","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121046366","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 : 2001-07-04DOI: 10.1109/EURCON.2001.938168
M. Ashibani, D. Mashao, B. Nleya
This paper introduces a multi-level multipath/link routing combined with prior estimation for residual bandwidth (PERB)-based bandwidth allocation scheme that seeks to efficiently allocate resources to bursts in real time. When a burst arrives, the extra required resources are searched from among predetermined paths. This approach not only reduces the overall delay time response, but also increases the chance of the bursts being accommodated in real-time.
{"title":"A multi level real-time bandwidth allocation scheme for ATM networks","authors":"M. Ashibani, D. Mashao, B. Nleya","doi":"10.1109/EURCON.2001.938168","DOIUrl":"https://doi.org/10.1109/EURCON.2001.938168","url":null,"abstract":"This paper introduces a multi-level multipath/link routing combined with prior estimation for residual bandwidth (PERB)-based bandwidth allocation scheme that seeks to efficiently allocate resources to bursts in real time. When a burst arrives, the extra required resources are searched from among predetermined paths. This approach not only reduces the overall delay time response, but also increases the chance of the bursts being accommodated in real-time.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121104107","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 : 2001-07-04DOI: 10.1109/EURCON.2001.937806
R. Stewart, R. Malayan, R. Roberts
This paper examines the development of communication theories and models from the process model of C.E. Shannon and W. Weaver (see "The Mathematical Theory of Communication", University of Illinois Press, Urbana, 1949) to a generalised communication model (see Stewart, R.W., IRNOP II Proceedings, 1998) and uses an example to show how this model is used to analyse organisation communications.
本文考察了沟通理论和模型的发展，从C.E.香农和W.韦弗的过程模型(见“沟通的数学理论”，伊利诺伊大学出版社，厄巴纳，1949年)到广义沟通模型(见斯图尔特，r.w.， IRNOP II Proceedings, 1998年)，并使用一个例子来展示如何使用该模型来分析组织沟通。
{"title":"The evolution and use of communication theories","authors":"R. Stewart, R. Malayan, R. Roberts","doi":"10.1109/EURCON.2001.937806","DOIUrl":"https://doi.org/10.1109/EURCON.2001.937806","url":null,"abstract":"This paper examines the development of communication theories and models from the process model of C.E. Shannon and W. Weaver (see \"The Mathematical Theory of Communication\", University of Illinois Press, Urbana, 1949) to a generalised communication model (see Stewart, R.W., IRNOP II Proceedings, 1998) and uses an example to show how this model is used to analyse organisation communications.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115334513","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：