Pub Date : 2004-09-27DOI: 10.1109/ISCCSP.2004.1296272
M. Ghorbel, A. Hamida, M. Samet
In this paper, a novel architecture of a programmable current-source based on miniaturized digital-to-analog converters (DAC) was proposed. Such new design would be dedicated to cochlear implant circuit. In this study, our main objective was to look for one model that could include, as close as possible, several criteria related to the implant functionality such as reliability, flexibility, energy efficiency and integration area. Hence, this 6-bit DAC architecture was conceived in order to be adequate for a programmable current-source. Our design was able to generate a 2mA maximum current through a 1K/spl Omega/ load, which is around the typical nerve impedance. Simulation results showed good linearity, low power consumption and a low area occupation. Resulting circuit was simulated by PSPICE tool using the 0.35/spl mu/m CMOS technology.
{"title":"Programmable current source dedicated to a cochlear implant","authors":"M. Ghorbel, A. Hamida, M. Samet","doi":"10.1109/ISCCSP.2004.1296272","DOIUrl":"https://doi.org/10.1109/ISCCSP.2004.1296272","url":null,"abstract":"In this paper, a novel architecture of a programmable current-source based on miniaturized digital-to-analog converters (DAC) was proposed. Such new design would be dedicated to cochlear implant circuit. In this study, our main objective was to look for one model that could include, as close as possible, several criteria related to the implant functionality such as reliability, flexibility, energy efficiency and integration area. Hence, this 6-bit DAC architecture was conceived in order to be adequate for a programmable current-source. Our design was able to generate a 2mA maximum current through a 1K/spl Omega/ load, which is around the typical nerve impedance. Simulation results showed good linearity, low power consumption and a low area occupation. Resulting circuit was simulated by PSPICE tool using the 0.35/spl mu/m CMOS technology.","PeriodicalId":146713,"journal":{"name":"First International Symposium on Control, Communications and Signal Processing, 2004.","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133365523","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 : 2004-09-27DOI: 10.1109/ISCCSP.2004.1296342
I. Jaafar, N. Youssef, H. Boujemaa
In this paper, a land mobile satellite model is presented. The new model is obtained by extension for the Hoyt model by adding to the received signal a light of sight component (LOS); this new model is the generalized Rice fading. Expressions of the probability density function (PDF) of level crossing rate (LCR) and average fade and no fade duration (AFD, ANFD) are given. Comparisons between results calculated from the model to simulations show reasonably good agreements. The generalized Rice model should be useful for designing of communications systems in light-shadowing environments.
{"title":"A generalized Rice channel for modeling mobile satellite link","authors":"I. Jaafar, N. Youssef, H. Boujemaa","doi":"10.1109/ISCCSP.2004.1296342","DOIUrl":"https://doi.org/10.1109/ISCCSP.2004.1296342","url":null,"abstract":"In this paper, a land mobile satellite model is presented. The new model is obtained by extension for the Hoyt model by adding to the received signal a light of sight component (LOS); this new model is the generalized Rice fading. Expressions of the probability density function (PDF) of level crossing rate (LCR) and average fade and no fade duration (AFD, ANFD) are given. Comparisons between results calculated from the model to simulations show reasonably good agreements. The generalized Rice model should be useful for designing of communications systems in light-shadowing environments.","PeriodicalId":146713,"journal":{"name":"First International Symposium on Control, Communications and Signal Processing, 2004.","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121791100","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 : 2004-09-27DOI: 10.1109/ISCCSP.2004.1296292
M. Windisch, G. Fettweis
A novel blind I/Q imbalance parameter estimation and compensation scheme for low-IF receivers, which was previously proposed by the authors, is analytically analyzed in this paper. As an outcome, we present an equation for calculating the expected power ratio of image and desired signal after compensation. The excellent performance of the novel compensation scheme, which was so far justified by simulations only, is now substantiated by a solid theory.
{"title":"Performance analysis for blind I/Q imbalance compensation in low-IF receivers","authors":"M. Windisch, G. Fettweis","doi":"10.1109/ISCCSP.2004.1296292","DOIUrl":"https://doi.org/10.1109/ISCCSP.2004.1296292","url":null,"abstract":"A novel blind I/Q imbalance parameter estimation and compensation scheme for low-IF receivers, which was previously proposed by the authors, is analytically analyzed in this paper. As an outcome, we present an equation for calculating the expected power ratio of image and desired signal after compensation. The excellent performance of the novel compensation scheme, which was so far justified by simulations only, is now substantiated by a solid theory.","PeriodicalId":146713,"journal":{"name":"First International Symposium on Control, Communications and Signal Processing, 2004.","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121858919","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 : 2004-09-27DOI: 10.1109/ISCCSP.2004.1296452
N. Jacobsen, G. Barriac, Upamanyu Madhow, Rong-Rong Chen, R. Koetter
We survey our recent results on approaching the performance limits of wireless time-varying channels. In current practice, transceivers for such channels employ a large fraction of training or pilot overhead for channel estimation and tracking, together with coherent reception assuming that the channel estimates are accurate. In this paper, we discuss our progress in developing an alternative noncoherent approach, in which the channel and data are estimated jointly, heavily leveraging iterative decoding techniques.
{"title":"Towards Shannon-theoretic limits on wireless time-varying channels","authors":"N. Jacobsen, G. Barriac, Upamanyu Madhow, Rong-Rong Chen, R. Koetter","doi":"10.1109/ISCCSP.2004.1296452","DOIUrl":"https://doi.org/10.1109/ISCCSP.2004.1296452","url":null,"abstract":"We survey our recent results on approaching the performance limits of wireless time-varying channels. In current practice, transceivers for such channels employ a large fraction of training or pilot overhead for channel estimation and tracking, together with coherent reception assuming that the channel estimates are accurate. In this paper, we discuss our progress in developing an alternative noncoherent approach, in which the channel and data are estimated jointly, heavily leveraging iterative decoding techniques.","PeriodicalId":146713,"journal":{"name":"First International Symposium on Control, Communications and Signal Processing, 2004.","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124201964","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 : 2004-09-27DOI: 10.1109/ISCCSP.2004.1296306
L. Chisci, R. Fantacci, F. Francioli, T. Pecorella
This paper presents a novel approach for dynamic bandwidth allocation in geo-stationary satellite networks. Each satellite gateway (SG) uses a local adaptive predictor to forecast the future input traffic flow along with a local predictive (receding-horizon) controller to generate a bandwidth request to the network control center (NCC). In turn, the NCC globally shares out the available bandwidth among the requesting SGs according to a suitable fair resource allocation policy. Simulation experiments demonstrate the effectiveness of the proposed approach in terms of efficient bandwidth usage and low packet delivery delays under different traffic load conditions.
{"title":"Dynamic bandwidth allocation via distributed predictive control in satellite networks","authors":"L. Chisci, R. Fantacci, F. Francioli, T. Pecorella","doi":"10.1109/ISCCSP.2004.1296306","DOIUrl":"https://doi.org/10.1109/ISCCSP.2004.1296306","url":null,"abstract":"This paper presents a novel approach for dynamic bandwidth allocation in geo-stationary satellite networks. Each satellite gateway (SG) uses a local adaptive predictor to forecast the future input traffic flow along with a local predictive (receding-horizon) controller to generate a bandwidth request to the network control center (NCC). In turn, the NCC globally shares out the available bandwidth among the requesting SGs according to a suitable fair resource allocation policy. Simulation experiments demonstrate the effectiveness of the proposed approach in terms of efficient bandwidth usage and low packet delivery delays under different traffic load conditions.","PeriodicalId":146713,"journal":{"name":"First International Symposium on Control, Communications and Signal Processing, 2004.","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130319791","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 : 2004-09-27DOI: 10.1109/ISCCSP.2004.1296430
S. Najeh, Hichem Besbes, A. Bouallègue
In a broadcasting system, the transmitter would be constrained to use a constellation, which can be demodulated by all the users and especially the users having the lowest signal to noise ratio (SNR). Choosing one type of modulation, would limit the reach of the broadcasting system. In this paper, we propose to use a simple watermarking system, to generate two classes of transmission on the same channel and using the same frequency plan. Basically, we will have like two channels running at the same symbol rate but with different constellation sizes: a slow channel and a fast channel. A slow channel is used to carry information at a lower constellation (QPSK for example) to users who have low SNR. The fast channel is used for the users who have high SNR. In fact, the channel, which uses the higher constellation, can be embedded on the QPSK signal without damaging the performance of the QPSK receiver. The obtained results agree with the statement of Costa on "writing on the dirty paper".
{"title":"A simple watermarking system","authors":"S. Najeh, Hichem Besbes, A. Bouallègue","doi":"10.1109/ISCCSP.2004.1296430","DOIUrl":"https://doi.org/10.1109/ISCCSP.2004.1296430","url":null,"abstract":"In a broadcasting system, the transmitter would be constrained to use a constellation, which can be demodulated by all the users and especially the users having the lowest signal to noise ratio (SNR). Choosing one type of modulation, would limit the reach of the broadcasting system. In this paper, we propose to use a simple watermarking system, to generate two classes of transmission on the same channel and using the same frequency plan. Basically, we will have like two channels running at the same symbol rate but with different constellation sizes: a slow channel and a fast channel. A slow channel is used to carry information at a lower constellation (QPSK for example) to users who have low SNR. The fast channel is used for the users who have high SNR. In fact, the channel, which uses the higher constellation, can be embedded on the QPSK signal without damaging the performance of the QPSK receiver. The obtained results agree with the statement of Costa on \"writing on the dirty paper\".","PeriodicalId":146713,"journal":{"name":"First International Symposium on Control, Communications and Signal Processing, 2004.","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128881367","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 : 2004-09-27DOI: 10.1109/ISCCSP.2004.1296226
Imed Bouazizi
In this work, we develop a framework for the estimation of distortion caused by packet loss. Video traffic carried over the Internet is often subject to congestion leading to packet loss and late arrivals. Depending on the characteristics of the transported video sequence and on the location of the lost packet data, the effects on the perceived video quality may vary considerably. We develop a practical model for the estimation of the distortion, introduced through some packet loss. We then deduce a metric for prioritizing video packets of a video flow for streaming over networks, based on the expected loss distortion in the perceived video quality. The evaluation of our model shows high accuracy in estimating video quality deterioration.
{"title":"Estimation of packet loss effects on video quality","authors":"Imed Bouazizi","doi":"10.1109/ISCCSP.2004.1296226","DOIUrl":"https://doi.org/10.1109/ISCCSP.2004.1296226","url":null,"abstract":"In this work, we develop a framework for the estimation of distortion caused by packet loss. Video traffic carried over the Internet is often subject to congestion leading to packet loss and late arrivals. Depending on the characteristics of the transported video sequence and on the location of the lost packet data, the effects on the perceived video quality may vary considerably. We develop a practical model for the estimation of the distortion, introduced through some packet loss. We then deduce a metric for prioritizing video packets of a video flow for streaming over networks, based on the expected loss distortion in the perceived video quality. The evaluation of our model shows high accuracy in estimating video quality deterioration.","PeriodicalId":146713,"journal":{"name":"First International Symposium on Control, Communications and Signal Processing, 2004.","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127992547","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 : 2004-09-27DOI: 10.1109/ISCCSP.2004.1296225
F. B. Amara, A. Jerbi, J. Au, F. Kossentini
A method is provided to avoid or otherwise reduce luminance and/or chrominance trailing artifacts in block-based hybrid video coders. The proposed trailing artifact avoidance approach has at its core three main components. The first component is a method to identify flat blocks in the source frame where the appearance of trailing artifacts would be very noticeable, and where flatness is determined according to several proposed criteria. The second component is a method to identify bad blocks, which refer to predicted blocks in motion estimation that correspond to flat blocks in the source frame and that contain trailing artifacts. The third component is a high performance motion estimation approach to avoid trailing artifacts when they are detected within a bad block. Experimental results using an H.264 based-coder indicate the proposed method is very effective in reducing or eliminating the appearance of trailing artifacts.
{"title":"Trailing artifact avoidance for low bit-rate block-based video coders","authors":"F. B. Amara, A. Jerbi, J. Au, F. Kossentini","doi":"10.1109/ISCCSP.2004.1296225","DOIUrl":"https://doi.org/10.1109/ISCCSP.2004.1296225","url":null,"abstract":"A method is provided to avoid or otherwise reduce luminance and/or chrominance trailing artifacts in block-based hybrid video coders. The proposed trailing artifact avoidance approach has at its core three main components. The first component is a method to identify flat blocks in the source frame where the appearance of trailing artifacts would be very noticeable, and where flatness is determined according to several proposed criteria. The second component is a method to identify bad blocks, which refer to predicted blocks in motion estimation that correspond to flat blocks in the source frame and that contain trailing artifacts. The third component is a high performance motion estimation approach to avoid trailing artifacts when they are detected within a bad block. Experimental results using an H.264 based-coder indicate the proposed method is very effective in reducing or eliminating the appearance of trailing artifacts.","PeriodicalId":146713,"journal":{"name":"First International Symposium on Control, Communications and Signal Processing, 2004.","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127854888","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 : 2004-09-27DOI: 10.1109/ISCCSP.2004.1296505
V. Lehtinen, D. Babic, M. Renfors
In this paper, the impulse response symmetry of Farrow interpolation filters and its significance in rational sample rate conversion is addressed. Four methods for ensuring impulse response symmetry are proposed. Comparison of different symmetrization schemes is made, with filters optimized based on the discrete-time impulse response model. The results indicate that optimization based on the discrete-time model often results in better performance than optimization based on the continuous-time model, and that there are significant performance differences between symmetrization schemes.
{"title":"On impulse response symmetry of Farrow interpolators in rational sample rate conversion","authors":"V. Lehtinen, D. Babic, M. Renfors","doi":"10.1109/ISCCSP.2004.1296505","DOIUrl":"https://doi.org/10.1109/ISCCSP.2004.1296505","url":null,"abstract":"In this paper, the impulse response symmetry of Farrow interpolation filters and its significance in rational sample rate conversion is addressed. Four methods for ensuring impulse response symmetry are proposed. Comparison of different symmetrization schemes is made, with filters optimized based on the discrete-time impulse response model. The results indicate that optimization based on the discrete-time model often results in better performance than optimization based on the continuous-time model, and that there are significant performance differences between symmetrization schemes.","PeriodicalId":146713,"journal":{"name":"First International Symposium on Control, Communications and Signal Processing, 2004.","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122778103","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 : 2004-09-27DOI: 10.1109/ISCCSP.2004.1296232
I. Darus, F. Aldebrez, M. Tokhi
System identification using parametric linear approaches for modelling a twin rotor multi-input multi-output system (TRMS) in hovering position is presented in this work. The utilisation of a genetic algorithm (GA) optimisation technique for dynamic modelling of a highly non-linear system is studied in comparison to the conventional recursive least squares (RLS) technique. The global search technique of GA is used to identify the parameters of the TRMS based on one-step-ahead prediction. A comparative assessment of the two models in characterising the system is carried out in the time and frequency domains. Experimental results indicate the advantages of GA over RLS in linear parametric modelling. The developed genetic-modelling approach will be used for control design and development in future work.
{"title":"Parametric modelling of a twin rotor system using genetic algorithms","authors":"I. Darus, F. Aldebrez, M. Tokhi","doi":"10.1109/ISCCSP.2004.1296232","DOIUrl":"https://doi.org/10.1109/ISCCSP.2004.1296232","url":null,"abstract":"System identification using parametric linear approaches for modelling a twin rotor multi-input multi-output system (TRMS) in hovering position is presented in this work. The utilisation of a genetic algorithm (GA) optimisation technique for dynamic modelling of a highly non-linear system is studied in comparison to the conventional recursive least squares (RLS) technique. The global search technique of GA is used to identify the parameters of the TRMS based on one-step-ahead prediction. A comparative assessment of the two models in characterising the system is carried out in the time and frequency domains. Experimental results indicate the advantages of GA over RLS in linear parametric modelling. The developed genetic-modelling approach will be used for control design and development in future work.","PeriodicalId":146713,"journal":{"name":"First International Symposium on Control, Communications and Signal Processing, 2004.","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117092457","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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