Pub Date : 2003-12-14DOI: 10.1109/ICECS.2003.1302043
Shaoping Chen, Tianren Yao
We introduce a novel space-time coding scheme, called space-time cyclic-delay coding (STCDC), for multiple input multiple output orthogonal frequency-division multiplexing (MIMO-OFDM) systems over frequency-selective fading channels. The scheme exploits the redundancy introduced by channel coding. The transmitter antennas send the cyclically delayed copies of OFDM symbols, and the receiver uses the maximum likelihood estimation method to estimate the transmitted sequence. We show that STCDC-OFDM can achieve the maximum diversity, which is the product of the number of transmitter antennas (N/sub t/), the number of receiver antennas (N/sub r/) and the channel length (L), if the error control code has at least a free distance of N/sub t/L. Compared with the existing space-time coding and space-frequency coded MIMO-OFDM techniques, the proposed scheme has the advantages of being independent from the number of transmit antennas and having a lower implementation complexity.
{"title":"A space-time coded multiantenna OFDM scheme over frequency-selective fading channels","authors":"Shaoping Chen, Tianren Yao","doi":"10.1109/ICECS.2003.1302043","DOIUrl":"https://doi.org/10.1109/ICECS.2003.1302043","url":null,"abstract":"We introduce a novel space-time coding scheme, called space-time cyclic-delay coding (STCDC), for multiple input multiple output orthogonal frequency-division multiplexing (MIMO-OFDM) systems over frequency-selective fading channels. The scheme exploits the redundancy introduced by channel coding. The transmitter antennas send the cyclically delayed copies of OFDM symbols, and the receiver uses the maximum likelihood estimation method to estimate the transmitted sequence. We show that STCDC-OFDM can achieve the maximum diversity, which is the product of the number of transmitter antennas (N/sub t/), the number of receiver antennas (N/sub r/) and the channel length (L), if the error control code has at least a free distance of N/sub t/L. Compared with the existing space-time coding and space-frequency coded MIMO-OFDM techniques, the proposed scheme has the advantages of being independent from the number of transmit antennas and having a lower implementation complexity.","PeriodicalId":36912,"journal":{"name":"Czas Kultury","volume":"81 1","pages":"328-331 Vol.1"},"PeriodicalIF":0.0,"publicationDate":"2003-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83769682","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 : 2003-12-14DOI: 10.1109/ICECS.2003.1302016
A. Abbasian, A. Afzali-Kusha
A novel logic family, called Pipeline Event-driven No-race Charge recycling Logic (PENCL), has been proposed and analyzed. PENCL improves power efficiency using an event detector circuit. In this new logic, when an event is detected on the input signal, the outputs are connected. This technique theoretically reduces the power consumption 50% compared to conventional charge recycling logic. The efficiency of the new method was analyzed using seven 2-input NAND gates connected to each other as a pipeline modular structure. This configuration was simulated with 0.35/spl mu/m technology using HSPICE. Simulation results show 43% power reduction using this new method compared to one of the most power efficient charge-recycling logic called race-Free CMOS Pass gate Charge recycling Logic (FCPCL). Dual rail isolated latch (DRIL), which is introduced for using in PENCL, has much better performance than the previous static latch.
{"title":"Pipeline Event-driven No-race Charge recycling Logic (PENCL) for low power application","authors":"A. Abbasian, A. Afzali-Kusha","doi":"10.1109/ICECS.2003.1302016","DOIUrl":"https://doi.org/10.1109/ICECS.2003.1302016","url":null,"abstract":"A novel logic family, called Pipeline Event-driven No-race Charge recycling Logic (PENCL), has been proposed and analyzed. PENCL improves power efficiency using an event detector circuit. In this new logic, when an event is detected on the input signal, the outputs are connected. This technique theoretically reduces the power consumption 50% compared to conventional charge recycling logic. The efficiency of the new method was analyzed using seven 2-input NAND gates connected to each other as a pipeline modular structure. This configuration was simulated with 0.35/spl mu/m technology using HSPICE. Simulation results show 43% power reduction using this new method compared to one of the most power efficient charge-recycling logic called race-Free CMOS Pass gate Charge recycling Logic (FCPCL). Dual rail isolated latch (DRIL), which is introduced for using in PENCL, has much better performance than the previous static latch.","PeriodicalId":36912,"journal":{"name":"Czas Kultury","volume":"18 1","pages":"220-223 Vol.1"},"PeriodicalIF":0.0,"publicationDate":"2003-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82662375","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 : 2003-12-14DOI: 10.1109/ICECS.2003.1301669
M. L. Tounsi, A. Khodja, B. Haraoubia
In this paper, we present an efficient variational technique for the analysis of the characteristics of multilayered directional couplers fabricated on anisotropic substrates on a quasi-static approach. Numerical results are presented for coupler designs in multilayered configurations. The variation of its characteristic parameters with crystal axis offsets is also reported. It is shown that high directivity can be achieved by making use of the substrate anisotropy in conjunction with a top cover to equalize even and odd-mode phase velocities.
{"title":"Enhancing performances of multilayered directional couplers on anisotropic substrates","authors":"M. L. Tounsi, A. Khodja, B. Haraoubia","doi":"10.1109/ICECS.2003.1301669","DOIUrl":"https://doi.org/10.1109/ICECS.2003.1301669","url":null,"abstract":"In this paper, we present an efficient variational technique for the analysis of the characteristics of multilayered directional couplers fabricated on anisotropic substrates on a quasi-static approach. Numerical results are presented for coupler designs in multilayered configurations. The variation of its characteristic parameters with crystal axis offsets is also reported. It is shown that high directivity can be achieved by making use of the substrate anisotropy in conjunction with a top cover to equalize even and odd-mode phase velocities.","PeriodicalId":36912,"journal":{"name":"Czas Kultury","volume":"16 1","pages":"966-969 Vol.3"},"PeriodicalIF":0.0,"publicationDate":"2003-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77753602","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 : 2003-12-14DOI: 10.1109/ICECS.2003.1301962
S. Hemati, A. Banihashemi
A new current-mode maximum winner-take-all (max WTA) circuit is presented. Inputs and output of the circuit are high swing, and voltage requirements for the inputs and the output are very low and just about V/sub eff/ (V/sub sat/) and 2 V/sub eff/ (2 V/sub sat/), respectively. Because of the cascode configuration, the proposed circuit shows very good precision even for short channel MOSFETs. Simulation results based on 0.13 /spl mu/m UMC CMOS technology are also presented. These results demonstrate the high-precision and low-voltage requirement of the circuit, which makes it a good choice for low-voltage min-sum analog iterative decoders and other soft computing applications.
{"title":"A current mode maximum winner-take-all circuit with low voltage requirement for min-sum analog iterative decoders","authors":"S. Hemati, A. Banihashemi","doi":"10.1109/ICECS.2003.1301962","DOIUrl":"https://doi.org/10.1109/ICECS.2003.1301962","url":null,"abstract":"A new current-mode maximum winner-take-all (max WTA) circuit is presented. Inputs and output of the circuit are high swing, and voltage requirements for the inputs and the output are very low and just about V/sub eff/ (V/sub sat/) and 2 V/sub eff/ (2 V/sub sat/), respectively. Because of the cascode configuration, the proposed circuit shows very good precision even for short channel MOSFETs. Simulation results based on 0.13 /spl mu/m UMC CMOS technology are also presented. These results demonstrate the high-precision and low-voltage requirement of the circuit, which makes it a good choice for low-voltage min-sum analog iterative decoders and other soft computing applications.","PeriodicalId":36912,"journal":{"name":"Czas Kultury","volume":"57 10 1","pages":"4-7 Vol.1"},"PeriodicalIF":0.0,"publicationDate":"2003-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81525916","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 : 2003-12-14DOI: 10.1109/ICECS.2003.1301918
S. Hosseini, M. Almaleki
This paper presents considerations on the switching frequency and duty cycle and operating equations of soft-switching buck chopper. These considerations are discussed and applied to selected soft-switching families such as ZVS-QRC, ZCS-QRC, ZVS-QSW-CV ZCS-QSW-CC, ZVT-PWM and ZCT-PWM (J.Abu. Qahouq and I. Batarseh, IEEE Trans. Power Electron., vol. 9, no. 5. pp. 684-691, 2002). The limitations on switching frequency and duty cycle are derived in terms of: chopper input voltage (V/sub g/), chopper output current (I/sub F/), resonant elements values including (C/sub n/ L/sub r/), voltage and current of filter capacitor and reactor or initial values of capacitor and reactor (V/sub i/, I/sub t/).
{"title":"Frequency & duty cycle control considerations for soft-switching buck chopper","authors":"S. Hosseini, M. Almaleki","doi":"10.1109/ICECS.2003.1301918","DOIUrl":"https://doi.org/10.1109/ICECS.2003.1301918","url":null,"abstract":"This paper presents considerations on the switching frequency and duty cycle and operating equations of soft-switching buck chopper. These considerations are discussed and applied to selected soft-switching families such as ZVS-QRC, ZCS-QRC, ZVS-QSW-CV ZCS-QSW-CC, ZVT-PWM and ZCT-PWM (J.Abu. Qahouq and I. Batarseh, IEEE Trans. Power Electron., vol. 9, no. 5. pp. 684-691, 2002). The limitations on switching frequency and duty cycle are derived in terms of: chopper input voltage (V/sub g/), chopper output current (I/sub F/), resonant elements values including (C/sub n/ L/sub r/), voltage and current of filter capacitor and reactor or initial values of capacitor and reactor (V/sub i/, I/sub t/).","PeriodicalId":36912,"journal":{"name":"Czas Kultury","volume":"23 1","pages":"842-845 Vol.2"},"PeriodicalIF":0.0,"publicationDate":"2003-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82802390","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 : 2003-12-14DOI: 10.1109/ICECS.2003.1302039
A. Abbasian, Amir Masoud Nasri-Nasrabadi, A. Afzali-Kusha
This paper describes modular energy recycling differential logic (MERDL). MERDL tries to achieve power efficiency by using a novel charge sharing method. In traditional charge sharing methods, half of the output capacitors' energy was lost during the output connection. In this scheme we try to recycle most of the lost energy back to the power supply. Implementation of the idea on a 2-input NAND gate showed about 30% improvement in power delay product compared with one of the most power efficient logic styles (i.e. NCRCPL).
{"title":"Modular energy recycling differential logic (MERDL) for low power application","authors":"A. Abbasian, Amir Masoud Nasri-Nasrabadi, A. Afzali-Kusha","doi":"10.1109/ICECS.2003.1302039","DOIUrl":"https://doi.org/10.1109/ICECS.2003.1302039","url":null,"abstract":"This paper describes modular energy recycling differential logic (MERDL). MERDL tries to achieve power efficiency by using a novel charge sharing method. In traditional charge sharing methods, half of the output capacitors' energy was lost during the output connection. In this scheme we try to recycle most of the lost energy back to the power supply. Implementation of the idea on a 2-input NAND gate showed about 30% improvement in power delay product compared with one of the most power efficient logic styles (i.e. NCRCPL).","PeriodicalId":36912,"journal":{"name":"Czas Kultury","volume":"46 1","pages":"312-315 Vol.1"},"PeriodicalIF":0.0,"publicationDate":"2003-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90815687","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 : 2003-12-14DOI: 10.1109/ICECS.2003.1301836
Ji Li, Qingfeng Xu, A. Elhakeem, M. Bennani, M. Kadoch
The application of FEC to multicast communication has seen significant developments recently. In this work, we have developed a new multi-session multicast QoS scheme using a hybrid proactive FEC/ARQ technique, and used a laboratory test-bed in order to evaluate this scheme. Our preliminary evaluation of hybrid proactive FEC/ARQ technique suggests shorter transmission time, decreased NAK traffic, and improved bandwidth utilization (reduced retransmission packets) when compared to the traditional ARQ reliable multicast technique.
{"title":"A practical proactive hybrid FEC/ARQ technique for reliable multi-session multicast communication","authors":"Ji Li, Qingfeng Xu, A. Elhakeem, M. Bennani, M. Kadoch","doi":"10.1109/ICECS.2003.1301836","DOIUrl":"https://doi.org/10.1109/ICECS.2003.1301836","url":null,"abstract":"The application of FEC to multicast communication has seen significant developments recently. In this work, we have developed a new multi-session multicast QoS scheme using a hybrid proactive FEC/ARQ technique, and used a laboratory test-bed in order to evaluate this scheme. Our preliminary evaluation of hybrid proactive FEC/ARQ technique suggests shorter transmission time, decreased NAK traffic, and improved bandwidth utilization (reduced retransmission packets) when compared to the traditional ARQ reliable multicast technique.","PeriodicalId":36912,"journal":{"name":"Czas Kultury","volume":"82 1","pages":"519-522 Vol.2"},"PeriodicalIF":0.0,"publicationDate":"2003-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86696908","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 : 2003-12-14DOI: 10.1109/ICECS.2003.1301681
U. Baroudi, A. Elhakeem
Future networks are expected to have the ability to accommodate variety of users, each with its own transmission characteristics and QoS requirements to be maintained. Compatible multiaccess system should provide the means to control (i.e. admission/congestion) the flow of traffic and at the same time maintain the QoS requirements. This paper investigates the performance of a novel measurement-based admission/congestion control policy over a hybrid TDMA/MC-CDMA platform. The practicality and several performance measures of the new system shall be analyzed analytically under a wide range of expected traffic characteristics (bit rate, transmission activities, etc.) for the future wireless networks. The adaptive admission/congestion control policy has effectively maintained the required QoS. It is worth to emphasize here that our proposed admission/congestion control polices apply preventive admission control as well as reactive congestion control.
{"title":"Adaptive admission/congestion control policy for hybrid TDMA/MC-CDMA integrated networks with guaranteed QoS","authors":"U. Baroudi, A. Elhakeem","doi":"10.1109/ICECS.2003.1301681","DOIUrl":"https://doi.org/10.1109/ICECS.2003.1301681","url":null,"abstract":"Future networks are expected to have the ability to accommodate variety of users, each with its own transmission characteristics and QoS requirements to be maintained. Compatible multiaccess system should provide the means to control (i.e. admission/congestion) the flow of traffic and at the same time maintain the QoS requirements. This paper investigates the performance of a novel measurement-based admission/congestion control policy over a hybrid TDMA/MC-CDMA platform. The practicality and several performance measures of the new system shall be analyzed analytically under a wide range of expected traffic characteristics (bit rate, transmission activities, etc.) for the future wireless networks. The adaptive admission/congestion control policy has effectively maintained the required QoS. It is worth to emphasize here that our proposed admission/congestion control polices apply preventive admission control as well as reactive congestion control.","PeriodicalId":36912,"journal":{"name":"Czas Kultury","volume":"45 1","pages":"1014-1017 Vol.3"},"PeriodicalIF":0.0,"publicationDate":"2003-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86437228","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 : 2003-12-14DOI: 10.1109/ICECS.2003.1301861
A. Alheraish, S. Alshebeili
Among current video traffic models, Autoregressive (AR) processes have been extensively used as good representation of variable bit rate (VBR) video services, due basically to their simplicity and case of computation. Recently, an elegant approach to the modeling of teleconferencing video has been proposed by Zhang [1999]. This approach decomposes the traffic data into a linear combination of a number of chi-square sequences, each of which is obtained by passing a Gaussian AR process through a simple nonlinearity. In this paper, we first show that the model presented by Zhang is a special case of the general form of models represented by quadratic filters that are widely used in modern digital signal processing. Second, we extend Zhang's approach to model MPEG video traffic; an important full motion video source that exhibits dynamic and complex pattern. Specifically, we propose modeling MPEG video at GOP layer in ATM packet switching networks.
{"title":"A gamma source model for full motion video using non-linear systems","authors":"A. Alheraish, S. Alshebeili","doi":"10.1109/ICECS.2003.1301861","DOIUrl":"https://doi.org/10.1109/ICECS.2003.1301861","url":null,"abstract":"Among current video traffic models, Autoregressive (AR) processes have been extensively used as good representation of variable bit rate (VBR) video services, due basically to their simplicity and case of computation. Recently, an elegant approach to the modeling of teleconferencing video has been proposed by Zhang [1999]. This approach decomposes the traffic data into a linear combination of a number of chi-square sequences, each of which is obtained by passing a Gaussian AR process through a simple nonlinearity. In this paper, we first show that the model presented by Zhang is a special case of the general form of models represented by quadratic filters that are widely used in modern digital signal processing. Second, we extend Zhang's approach to model MPEG video traffic; an important full motion video source that exhibits dynamic and complex pattern. Specifically, we propose modeling MPEG video at GOP layer in ATM packet switching networks.","PeriodicalId":36912,"journal":{"name":"Czas Kultury","volume":"70 1","pages":"619-622 Vol.2"},"PeriodicalIF":0.0,"publicationDate":"2003-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88312423","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 : 2003-12-14DOI: 10.1109/ICECS.2003.1301685
T. Hämäläinen, Mikko Pääkkönen, J. Joutsensalo, A. Sayenko, Mikko Ketola
This paper explores mechanisms that will enable network service providers to optimize their operations and make them economically viable, and to provide, through pricing, sufficient attractions to users of network services that will help smooth spikes in demand and lead to a more efficient utilization of the available resources. Proposed model for charging and traffic allocation is suitable for an integrated service network.
{"title":"QoS- and revenue aware adaptive scheduling algorithm","authors":"T. Hämäläinen, Mikko Pääkkönen, J. Joutsensalo, A. Sayenko, Mikko Ketola","doi":"10.1109/ICECS.2003.1301685","DOIUrl":"https://doi.org/10.1109/ICECS.2003.1301685","url":null,"abstract":"This paper explores mechanisms that will enable network service providers to optimize their operations and make them economically viable, and to provide, through pricing, sufficient attractions to users of network services that will help smooth spikes in demand and lead to a more efficient utilization of the available resources. Proposed model for charging and traffic allocation is suitable for an integrated service network.","PeriodicalId":36912,"journal":{"name":"Czas Kultury","volume":"23 1","pages":"1030-1033 Vol.3"},"PeriodicalIF":0.0,"publicationDate":"2003-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76030023","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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