Pub Date : 2001-07-04DOI: 10.1109/EURCON.2001.937786
D. Bruckmann
In a digital receiver with broadband signal sampling, digital decimation filters are required. The signal is sampled and digitised in such an architecture by a properly designed quantiser and the decimation stages after the quantiser should be programmable to provide flexibility. In this contribution, a new architecture for the implementation of high-order, programmable decimation filters is described. Using this filter concept, the flexibility with respect to multimode capability and the degree of integration can be drastically increased. It will be shown that the use of cascaded low-order wave digital lattice filters for the lower decimation filter stages results in a number of advantages compared to standard methods. By properly selecting the number of lattice filter cells and optimising the filter coefficients, a very efficient realisation is possible in VLSI-technology. Due to the simple filter structures and since no general multiplier is needed, significant hardware reduction can be obtained compared to existing solutions.
{"title":"Optimised decimation stages with lattice wave digital filters for a flexible digital receiver architecture","authors":"D. Bruckmann","doi":"10.1109/EURCON.2001.937786","DOIUrl":"https://doi.org/10.1109/EURCON.2001.937786","url":null,"abstract":"In a digital receiver with broadband signal sampling, digital decimation filters are required. The signal is sampled and digitised in such an architecture by a properly designed quantiser and the decimation stages after the quantiser should be programmable to provide flexibility. In this contribution, a new architecture for the implementation of high-order, programmable decimation filters is described. Using this filter concept, the flexibility with respect to multimode capability and the degree of integration can be drastically increased. It will be shown that the use of cascaded low-order wave digital lattice filters for the lower decimation filter stages results in a number of advantages compared to standard methods. By properly selecting the number of lattice filter cells and optimising the filter coefficients, a very efficient realisation is possible in VLSI-technology. Due to the simple filter structures and since no general multiplier is needed, significant hardware reduction can be obtained compared to existing solutions.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"16 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":"114759606","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.2001.938129
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.2001.937776
D. Matolak
Much recent interest has been focused upon third-generation cellular systems, particularly wideband code division multiple access (WCDMA). Deployments must consider scarce available spectrum, so researchers have been investigating spectral overlay, as a means of increasing capacity. Spectral overlay may also be a method used during transition from current to future systems. Based upon a method developed in Matolak (2000), we estimate capacities of WCDMA when overlaid upon the Global System for Mobile communication (GSM). This method is an improvement upon the standard technique for approximating multiuser interference (MUI), and is more general than previous work in that it allows for different values of data rate within each system, an arbitrary number of overlaid CDMA systems, inclusion of outside-cell as well as outside-system interferences, and narrowband interferers. We apply the method to GSM and WCDMA, and explore via several examples the capacities achievable as a function of several system parameters, including the number of GSM frequency allocations, relative power levels, and a number of different data rates.
{"title":"Capacity estimation for spectrally-overlaid WCDMA & GSM systems","authors":"D. Matolak","doi":"10.1109/EURCON.2001.937776","DOIUrl":"https://doi.org/10.1109/EURCON.2001.937776","url":null,"abstract":"Much recent interest has been focused upon third-generation cellular systems, particularly wideband code division multiple access (WCDMA). Deployments must consider scarce available spectrum, so researchers have been investigating spectral overlay, as a means of increasing capacity. Spectral overlay may also be a method used during transition from current to future systems. Based upon a method developed in Matolak (2000), we estimate capacities of WCDMA when overlaid upon the Global System for Mobile communication (GSM). This method is an improvement upon the standard technique for approximating multiuser interference (MUI), and is more general than previous work in that it allows for different values of data rate within each system, an arbitrary number of overlaid CDMA systems, inclusion of outside-cell as well as outside-system interferences, and narrowband interferers. We apply the method to GSM and WCDMA, and explore via several examples the capacities achievable as a function of several system parameters, including the number of GSM frequency allocations, relative power levels, and a number of different data rates.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"41 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":"115474780","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.2001.938108
J. Stergar, B. Horvat
In our paper, we present different approaches to designing multimedia presentations with multimedia authoring tools. We present different possibilities in implementing media (such as text, graphics, animation, sound and video) in one such authoring tool and compare its capabilities for managing and manipulating media compared with other multimedia authoring tools. The heart of the matter is an interactive tutorial (multimedia presentation) designed with a flow chart based authoring tool. The main goal of this tutorial is in tutoring the basics of MM design with Authorware and concerns built-in functions (additional presentations are also built with such a multimedia authoring approach) supported in the flow chart based approach to multimedia authoring. We designed the tutoring tool with the concept of distance learning and user testing over the Internet. In our discussion, we emphasize distance learning and conclude with an approach controlling user interactivity within the flow chart based multimedia presentations.
{"title":"Distance learning approach in multimedia tutoring","authors":"J. Stergar, B. Horvat","doi":"10.1109/EURCON.2001.938108","DOIUrl":"https://doi.org/10.1109/EURCON.2001.938108","url":null,"abstract":"In our paper, we present different approaches to designing multimedia presentations with multimedia authoring tools. We present different possibilities in implementing media (such as text, graphics, animation, sound and video) in one such authoring tool and compare its capabilities for managing and manipulating media compared with other multimedia authoring tools. The heart of the matter is an interactive tutorial (multimedia presentation) designed with a flow chart based authoring tool. The main goal of this tutorial is in tutoring the basics of MM design with Authorware and concerns built-in functions (additional presentations are also built with such a multimedia authoring approach) supported in the flow chart based approach to multimedia authoring. We designed the tutoring tool with the concept of distance learning and user testing over the Internet. In our discussion, we emphasize distance learning and conclude with an approach controlling user interactivity within the flow chart based multimedia presentations.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"39 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":"125068026","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.2001.938170
P. Homan, J. Bester
The possibility of enabling quality of service in input-queued packet switches has been investigated. An expanded version of the maximum weight matching (MWM) scheduling mechanism has been proposed by including additional weight calculation algorithms. The overall results are quite satisfactory. Clearly, the performance of output-queued packet switches cannot be achieved, but controlled service class separation is possible. For example, by using the weighted fair queuing (WFQ) weight calculation algorithm, fair bandwidth distribution can be achieved.
{"title":"Enabling quality of service in input-queued packet switches","authors":"P. Homan, J. Bester","doi":"10.1109/EURCON.2001.938170","DOIUrl":"https://doi.org/10.1109/EURCON.2001.938170","url":null,"abstract":"The possibility of enabling quality of service in input-queued packet switches has been investigated. An expanded version of the maximum weight matching (MWM) scheduling mechanism has been proposed by including additional weight calculation algorithms. The overall results are quite satisfactory. Clearly, the performance of output-queued packet switches cannot be achieved, but controlled service class separation is possible. For example, by using the weighted fair queuing (WFQ) weight calculation algorithm, fair bandwidth distribution can be achieved.","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":"129747539","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.2001.937795
Xiaoxiao. Zhou, Jianbo Liu, Wen-tao Song, Han-wen Luo
This extended abstract presents a new class of codes, chaotic turbo codes, which can be used in chaotic secure communication for mobile systems. In our research, the conventional turbo codes and chaotic digital encoder are implemented together in an effective way. After a lot of simulation, we found that chaotic turbo codes bring some important properties to both turbo codes and chaotic secure communication. We have also made great efforts into developing and evaluating some practical chaotic iterative decoding algorithms for efficient exploitation.
{"title":"Chaotic turbo codes in secure communication","authors":"Xiaoxiao. Zhou, Jianbo Liu, Wen-tao Song, Han-wen Luo","doi":"10.1109/EURCON.2001.937795","DOIUrl":"https://doi.org/10.1109/EURCON.2001.937795","url":null,"abstract":"This extended abstract presents a new class of codes, chaotic turbo codes, which can be used in chaotic secure communication for mobile systems. In our research, the conventional turbo codes and chaotic digital encoder are implemented together in an effective way. After a lot of simulation, we found that chaotic turbo codes bring some important properties to both turbo codes and chaotic secure communication. We have also made great efforts into developing and evaluating some practical chaotic iterative decoding algorithms for efficient exploitation.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"74 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":"115959441","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.2001.937788
E. Udvary
An experimental and theoretical study is presented for the transmission and noise characteristics of semiconductor optical amplifiers (SOAs). This device is very relevant in the novel optical networks. So the gain and noise performance are important in all the linear and nonlinear regimes. The paper exhibits the main SOA characteristics which were also measured.
{"title":"Noise performance of semiconductor optical amplifiers","authors":"E. Udvary","doi":"10.1109/EURCON.2001.937788","DOIUrl":"https://doi.org/10.1109/EURCON.2001.937788","url":null,"abstract":"An experimental and theoretical study is presented for the transmission and noise characteristics of semiconductor optical amplifiers (SOAs). This device is very relevant in the novel optical networks. So the gain and noise performance are important in all the linear and nonlinear regimes. The paper exhibits the main SOA characteristics which were also measured.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"13 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":"114856313","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.2001.938136
D. Draca, M. Stefanovic, A. Vidovic
Summary form only given. In this paper, the phase error in the MSK (minimum shift keying) receiver carrier and crosstalk between the I and Q channels are assumed. Also, the phase error is a random variable due to noise and other random input processes. Here, besides this imperfect carrier extraction, interference due to communication channel features is assumed. Since the interference can be the consequence of different events, the interference phase has uniform distribution. The influence of the imperfect reference signal extraction is expressed by the probability density function of the first order PLL (phase locked loop) phase error. The distribution parameters depend on the PLL structure, the equivalent noise bandwidth of the loop, the loop gain, the useful signal as well as the interference at the receiver input. For the presentation of this problem, the error rate, as a measure of the quality of the digital system, is calculated numerically and the detailed analysis of the obtained results is performed.
{"title":"Influence of noisy carrier reference signal and interference on error probability of MSK correlative receiver","authors":"D. Draca, M. Stefanovic, A. Vidovic","doi":"10.1109/EURCON.2001.938136","DOIUrl":"https://doi.org/10.1109/EURCON.2001.938136","url":null,"abstract":"Summary form only given. In this paper, the phase error in the MSK (minimum shift keying) receiver carrier and crosstalk between the I and Q channels are assumed. Also, the phase error is a random variable due to noise and other random input processes. Here, besides this imperfect carrier extraction, interference due to communication channel features is assumed. Since the interference can be the consequence of different events, the interference phase has uniform distribution. The influence of the imperfect reference signal extraction is expressed by the probability density function of the first order PLL (phase locked loop) phase error. The distribution parameters depend on the PLL structure, the equivalent noise bandwidth of the loop, the loop gain, the useful signal as well as the interference at the receiver input. For the presentation of this problem, the error rate, as a measure of the quality of the digital system, is calculated numerically and the detailed analysis of the obtained results is performed.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"27 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":"132301517","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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