Pub Date : 2003-10-15DOI: 10.1109/TENCON.2003.1273267
K. Barman, K. Sriram, V. Reddy
In OFDM (orthogonal frequency division multiplexing) based communication systems, convolutional codes are used along with bit interleaving to counter the effect of burst errors. The receiver, on the other hand, performs de-interleaving and decodes the received bit sequence using the Viterbi algorithm (VA). One obvious choice for this type of decoding is to use the Hamming distance and hard decision VA. The performance of a metric based on the Euclidean distance, allowing a soft-decision Viterbi decoding on the received de-interleaved bit sequence, is studied. Unlike conventional soft-decision Viterbi decoding, demodulated bits are assigned soft metrics based on the corresponding received symbol. It is observed from simulations that bit error rate (BER) performance using this metric is very close to the conventional symbol based soft-decision Viterbi decoding which can be applied when bit interleaving is not incorporated. We also discuss a modified metric using the frequency domain equalizer (FDE) taps in the case of multipath channels, which yields better packet error rate (PER) performance.
{"title":"Performance of a sub-optimal metric for soft-decision Viterbi with bit interleaving in OFDM based systems","authors":"K. Barman, K. Sriram, V. Reddy","doi":"10.1109/TENCON.2003.1273267","DOIUrl":"https://doi.org/10.1109/TENCON.2003.1273267","url":null,"abstract":"In OFDM (orthogonal frequency division multiplexing) based communication systems, convolutional codes are used along with bit interleaving to counter the effect of burst errors. The receiver, on the other hand, performs de-interleaving and decodes the received bit sequence using the Viterbi algorithm (VA). One obvious choice for this type of decoding is to use the Hamming distance and hard decision VA. The performance of a metric based on the Euclidean distance, allowing a soft-decision Viterbi decoding on the received de-interleaved bit sequence, is studied. Unlike conventional soft-decision Viterbi decoding, demodulated bits are assigned soft metrics based on the corresponding received symbol. It is observed from simulations that bit error rate (BER) performance using this metric is very close to the conventional symbol based soft-decision Viterbi decoding which can be applied when bit interleaving is not incorporated. We also discuss a modified metric using the frequency domain equalizer (FDE) taps in the case of multipath channels, which yields better packet error rate (PER) performance.","PeriodicalId":405847,"journal":{"name":"TENCON 2003. Conference on Convergent Technologies for Asia-Pacific Region","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127668647","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 : 2003-10-15DOI: 10.1109/TENCON.2003.1273170
D. Loganathan, J. Amudha, K. Mehata
Fractal image compression receives much attention because of its desirable properties like resolution independence, fast decoding and very competitive rate-distortion curves. Despite the advances made in fractal image compression the long computing time in encoding phase still remain as main drawback of this technique as encoding step is computationally expensive. A large number of sequential searches through portions of the image are carried out to identify best matches for other image portions. So far, several methods have been proposed in order to speed-up fractal image coding. Here an attempt is made to analyze the speed-up techniques like classification and feature vector, which demonstrates the search through larger portions of the domain pool without increasing computation time. In this way both the image quality and compression ratio are improved at reduced computation time. Experimental results and analysis show that proposed method can speed up fractal image encoding process over conventional methods.
{"title":"Classification and feature vector techniques to improve fractal image coding","authors":"D. Loganathan, J. Amudha, K. Mehata","doi":"10.1109/TENCON.2003.1273170","DOIUrl":"https://doi.org/10.1109/TENCON.2003.1273170","url":null,"abstract":"Fractal image compression receives much attention because of its desirable properties like resolution independence, fast decoding and very competitive rate-distortion curves. Despite the advances made in fractal image compression the long computing time in encoding phase still remain as main drawback of this technique as encoding step is computationally expensive. A large number of sequential searches through portions of the image are carried out to identify best matches for other image portions. So far, several methods have been proposed in order to speed-up fractal image coding. Here an attempt is made to analyze the speed-up techniques like classification and feature vector, which demonstrates the search through larger portions of the domain pool without increasing computation time. In this way both the image quality and compression ratio are improved at reduced computation time. Experimental results and analysis show that proposed method can speed up fractal image encoding process over conventional methods.","PeriodicalId":405847,"journal":{"name":"TENCON 2003. Conference on Convergent Technologies for Asia-Pacific Region","volume":"166 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126226380","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 : 2003-10-15DOI: 10.1109/TENCON.2003.1273187
K. Vittal, D.N. Gaonakar, D.B. Fakruddin
This paper proposes the wavelet transform (WT) based algorithm useful in digital differential protection of transformer. It is shown that, the wavelet transform has more distinct feature extraction property, due to its ability to extract information from the transient signals, simultaneously both in time and frequency. A decision logic has been devised using extracted feature from differential current, so as to distinguish an internal fault from an inrush/over-excitation. The proposed algorithm is evaluated using simulated inrush, over-excitation and internal fault current signals. For this purpose a transient behavioral model of power transformer has been developed using Matlab software. Results of evaluation study show that the proposed WT based differential protection scheme can overcome the problem of false tripping due to inrush/over-excitation.
{"title":"Development of wavelet transform based numeric relay for differential protection of power transformer","authors":"K. Vittal, D.N. Gaonakar, D.B. Fakruddin","doi":"10.1109/TENCON.2003.1273187","DOIUrl":"https://doi.org/10.1109/TENCON.2003.1273187","url":null,"abstract":"This paper proposes the wavelet transform (WT) based algorithm useful in digital differential protection of transformer. It is shown that, the wavelet transform has more distinct feature extraction property, due to its ability to extract information from the transient signals, simultaneously both in time and frequency. A decision logic has been devised using extracted feature from differential current, so as to distinguish an internal fault from an inrush/over-excitation. The proposed algorithm is evaluated using simulated inrush, over-excitation and internal fault current signals. For this purpose a transient behavioral model of power transformer has been developed using Matlab software. Results of evaluation study show that the proposed WT based differential protection scheme can overcome the problem of false tripping due to inrush/over-excitation.","PeriodicalId":405847,"journal":{"name":"TENCON 2003. Conference on Convergent Technologies for Asia-Pacific Region","volume":"118 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128169729","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 : 2003-10-15DOI: 10.1109/TENCON.2003.1273156
Sujian Zhao, Cong Shen, Xin Su, Yan Yao
Conventional software radio architectures cannot perform signal processing using application level software or have limited capability. To solve these problems, this paper proposes a new architecture that can perform signal processing using application level software on cluster of workstations. This paper introduces key technologies from RF to baseband. Especially, detail designs are given for core technologies of PCI card and parallel processing. Based on these principles, wireless voice communications for four standards are realized on the system. Theory and practice prove that this is a scalable, more ideal software radio and is a promising one with potential.
{"title":"Architecture of a software radio system based on cluster of workstations","authors":"Sujian Zhao, Cong Shen, Xin Su, Yan Yao","doi":"10.1109/TENCON.2003.1273156","DOIUrl":"https://doi.org/10.1109/TENCON.2003.1273156","url":null,"abstract":"Conventional software radio architectures cannot perform signal processing using application level software or have limited capability. To solve these problems, this paper proposes a new architecture that can perform signal processing using application level software on cluster of workstations. This paper introduces key technologies from RF to baseband. Especially, detail designs are given for core technologies of PCI card and parallel processing. Based on these principles, wireless voice communications for four standards are realized on the system. Theory and practice prove that this is a scalable, more ideal software radio and is a promising one with potential.","PeriodicalId":405847,"journal":{"name":"TENCON 2003. Conference on Convergent Technologies for Asia-Pacific Region","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125425905","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 : 2003-10-15DOI: 10.1109/TENCON.2003.1273258
S. Kundu, S. Chakrabarti
The outage and minimum duration outage probability of a voice user is evaluated in the presence of data users, considering correlation among signal and interferers. Also, the bit error rate (BER) of a data user is evaluated in the same scenario. Stronger correlation lowers the outage and minimum duration outage probability as well as the BER of data. The effect of power control on BER is studied and higher PCE (power control error) is found to increase the BER.
{"title":"Performance of packet voice/data integrated service in cellular CDMA with correlated interferers","authors":"S. Kundu, S. Chakrabarti","doi":"10.1109/TENCON.2003.1273258","DOIUrl":"https://doi.org/10.1109/TENCON.2003.1273258","url":null,"abstract":"The outage and minimum duration outage probability of a voice user is evaluated in the presence of data users, considering correlation among signal and interferers. Also, the bit error rate (BER) of a data user is evaluated in the same scenario. Stronger correlation lowers the outage and minimum duration outage probability as well as the BER of data. The effect of power control on BER is studied and higher PCE (power control error) is found to increase the BER.","PeriodicalId":405847,"journal":{"name":"TENCON 2003. Conference on Convergent Technologies for Asia-Pacific Region","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127991921","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 : 2003-10-15DOI: 10.1109/TENCON.2003.1273159
P. Kondekar
The superjunction (SJ) layer for 600 V is analytically designed for perfect charge balance and compared with SJ MOSFET, where the channel region creates charge imbalance due to unsymmetrical drift layer. We estimated this imbalance created due to the channel region with the help simulation. In order to simulate the SJ MOSFET with physical limitations of the fabrication technology, we have deliberately introduced the imbalance in SJ drift layer by varying the doping density of p pillar and then of n drift layer up to 10% respectively. The effect of this imbalance on the off state and on the on state breakdown voltage of the device investigated in detail with the help of simulation.
{"title":"Static off state and conduction state charge imbalance in the superjunction power MOSFET","authors":"P. Kondekar","doi":"10.1109/TENCON.2003.1273159","DOIUrl":"https://doi.org/10.1109/TENCON.2003.1273159","url":null,"abstract":"The superjunction (SJ) layer for 600 V is analytically designed for perfect charge balance and compared with SJ MOSFET, where the channel region creates charge imbalance due to unsymmetrical drift layer. We estimated this imbalance created due to the channel region with the help simulation. In order to simulate the SJ MOSFET with physical limitations of the fabrication technology, we have deliberately introduced the imbalance in SJ drift layer by varying the doping density of p pillar and then of n drift layer up to 10% respectively. The effect of this imbalance on the off state and on the on state breakdown voltage of the device investigated in detail with the help of simulation.","PeriodicalId":405847,"journal":{"name":"TENCON 2003. Conference on Convergent Technologies for Asia-Pacific Region","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132492019","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 : 2003-10-15DOI: 10.1109/TENCON.2003.1273337
R. Kumar
The growth of the Internet has brought with it a tremendous volume of multimedia traffic, which is bursty in nature. Providing a required QoS as well as modeling multimedia traffic has been a challenging task. We transcode multimedia data to cater for low bandwidth availability and different end-user requirements. We propose a protocol architecture which has been developed by the amalgamation of well-known components and which provides guaranteed multimedia communication over the Internet. We model multimedia traffic using the M/Pareto distribution in an attempt to represent realistic traffic patterns. We use the semantics of multimedia data-streams for rate adaptation transcoding to avoid network congestion and to ensure optimal use of network resources. The impact of transcoding the multimedia data to suit it to the network load and the end user requirements is also studied. Simulation results are presented and compared.
{"title":"A rate adaptation transcoding to support QoS over Internet for multimedia traffic","authors":"R. Kumar","doi":"10.1109/TENCON.2003.1273337","DOIUrl":"https://doi.org/10.1109/TENCON.2003.1273337","url":null,"abstract":"The growth of the Internet has brought with it a tremendous volume of multimedia traffic, which is bursty in nature. Providing a required QoS as well as modeling multimedia traffic has been a challenging task. We transcode multimedia data to cater for low bandwidth availability and different end-user requirements. We propose a protocol architecture which has been developed by the amalgamation of well-known components and which provides guaranteed multimedia communication over the Internet. We model multimedia traffic using the M/Pareto distribution in an attempt to represent realistic traffic patterns. We use the semantics of multimedia data-streams for rate adaptation transcoding to avoid network congestion and to ensure optimal use of network resources. The impact of transcoding the multimedia data to suit it to the network load and the end user requirements is also studied. Simulation results are presented and compared.","PeriodicalId":405847,"journal":{"name":"TENCON 2003. Conference on Convergent Technologies for Asia-Pacific Region","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130439407","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 : 2003-10-15DOI: 10.1109/TENCON.2003.1273350
S. Laxman, P. S. Sastry
This paper proposes a new method for text-dependent speaker recognition. The scheme is based on learning (what we refer to as) speaker-specific compensators for each speaker in the system. The compensator is essentially a speaker to speaker transformation which enables the recognition of the speech of one speaker through a speaker-dependent speech recognition system built for the other. Such a transformation, adequate for our purposes, may be achieved by a simple vector addition in the cepstral domain. This speaker-specific compensator captures the characteristics of the speaker we wish to recognize. For each speaker who is registered into the system, we learn a unique set of compensators. The speaker recognition decision is then based on which compensator achieves best speech recognition scores.
{"title":"Text-dependent speaker recognition using speaker specific compensation","authors":"S. Laxman, P. S. Sastry","doi":"10.1109/TENCON.2003.1273350","DOIUrl":"https://doi.org/10.1109/TENCON.2003.1273350","url":null,"abstract":"This paper proposes a new method for text-dependent speaker recognition. The scheme is based on learning (what we refer to as) speaker-specific compensators for each speaker in the system. The compensator is essentially a speaker to speaker transformation which enables the recognition of the speech of one speaker through a speaker-dependent speech recognition system built for the other. Such a transformation, adequate for our purposes, may be achieved by a simple vector addition in the cepstral domain. This speaker-specific compensator captures the characteristics of the speaker we wish to recognize. For each speaker who is registered into the system, we learn a unique set of compensators. The speaker recognition decision is then based on which compensator achieves best speech recognition scores.","PeriodicalId":405847,"journal":{"name":"TENCON 2003. Conference on Convergent Technologies for Asia-Pacific Region","volume":"144 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127559382","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 : 2003-10-15DOI: 10.1109/TENCON.2003.1273180
A. Raut, A. Basavaraja
First generation enterprise application integration (hereinafter, "EAl") focused on data integration and stressed on converting data between disparate formats. Then enterprises looked for integrating packages at the application level. That led to brittle and point-to-point connections between the applications allowing them to share information with other systems inside or outside of the organization. This information oriented point-to-point application integration has been quite popular for some time before the enterprises understood the importance of business processes to sustain continuous growth and profit in extremely tough market conditions. To align the business vision of an organization with the business processes, software architects are looking at the application integration at a higher level of abstraction called enterprises business process integration. This model allows the exchange of information between the applications as a part of a business process which is controlled by a business process management (hereinafter, "BPM") package. This paper discusses about the issues involved with traditional EAI approaches and how business process integration (hereinafter, "BPI") can overcome these issues. It presents an architectural approach to the business process integration that highlights the ideal integration methodologies for applications both inside and outside of the organization leveraging the latest technologies like Web services and XML messaging.
{"title":"Enterprise business process integration","authors":"A. Raut, A. Basavaraja","doi":"10.1109/TENCON.2003.1273180","DOIUrl":"https://doi.org/10.1109/TENCON.2003.1273180","url":null,"abstract":"First generation enterprise application integration (hereinafter, \"EAl\") focused on data integration and stressed on converting data between disparate formats. Then enterprises looked for integrating packages at the application level. That led to brittle and point-to-point connections between the applications allowing them to share information with other systems inside or outside of the organization. This information oriented point-to-point application integration has been quite popular for some time before the enterprises understood the importance of business processes to sustain continuous growth and profit in extremely tough market conditions. To align the business vision of an organization with the business processes, software architects are looking at the application integration at a higher level of abstraction called enterprises business process integration. This model allows the exchange of information between the applications as a part of a business process which is controlled by a business process management (hereinafter, \"BPM\") package. This paper discusses about the issues involved with traditional EAI approaches and how business process integration (hereinafter, \"BPI\") can overcome these issues. It presents an architectural approach to the business process integration that highlights the ideal integration methodologies for applications both inside and outside of the organization leveraging the latest technologies like Web services and XML messaging.","PeriodicalId":405847,"journal":{"name":"TENCON 2003. Conference on Convergent Technologies for Asia-Pacific Region","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130829333","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 : 2003-10-15DOI: 10.1109/TENCON.2003.1273201
J. Manivannan, M. R. Reddy, S. Thanikachalam, R. Varghese
In this paper we propose a new method for edge detection in ultrasound images by using a fuzzy inference system (FIS). The input image is preprocessed and the difference in intensities of each pixel to its neighborhood is given as input to the FIS. Depending on the magnitude of differences, sufficient inference rules were defined in the system to get the edges even in the low contrast region. This method is successfully applied to the echocardiogram images to detect the left ventricle (LV) endocardial borders and some experiments are given.
{"title":"Endocardial edge detection by fuzzy inference system","authors":"J. Manivannan, M. R. Reddy, S. Thanikachalam, R. Varghese","doi":"10.1109/TENCON.2003.1273201","DOIUrl":"https://doi.org/10.1109/TENCON.2003.1273201","url":null,"abstract":"In this paper we propose a new method for edge detection in ultrasound images by using a fuzzy inference system (FIS). The input image is preprocessed and the difference in intensities of each pixel to its neighborhood is given as input to the FIS. Depending on the magnitude of differences, sufficient inference rules were defined in the system to get the edges even in the low contrast region. This method is successfully applied to the echocardiogram images to detect the left ventricle (LV) endocardial borders and some experiments are given.","PeriodicalId":405847,"journal":{"name":"TENCON 2003. Conference on Convergent Technologies for Asia-Pacific Region","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132864076","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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