Pub Date : 2007-12-04DOI: 10.1109/ISCIT.2007.4392104
Yachen Wang, G. Xie, Yuan'an Liu, Na Li
This paper puts forward two novel user-grouping algorithms for grouped MC-CDMA systems. The adaptive assignment for user-grouping plays an important role for link quality. We formulate the capacity-maximizing problem of user-grouping and analysis the optimal criterion for it. The derived optimal criterion has a similar form with signal to noise plus interference (SINR), with unassigned power included. Thus the unassigned power leads to an unpractical usage. We then investigate user's equivalent SINR for minimum mean square error (MMSE) detection serving as assignment criterion, and propose two kinds of user-grouping algorithms. In these algorithms, only partial channel information is needed at the base station, which saves a large part of bandwidth occupying by feedback information. The proposed algorithms are evaluated by computer simulations to be prior to the conventional algorithm at both BER performance and data rate. Meanwhile, they have a lower implementation complexity for practical reality.
{"title":"Feasible resource allocation with partial channel information for grouped MC-CDMA systems","authors":"Yachen Wang, G. Xie, Yuan'an Liu, Na Li","doi":"10.1109/ISCIT.2007.4392104","DOIUrl":"https://doi.org/10.1109/ISCIT.2007.4392104","url":null,"abstract":"This paper puts forward two novel user-grouping algorithms for grouped MC-CDMA systems. The adaptive assignment for user-grouping plays an important role for link quality. We formulate the capacity-maximizing problem of user-grouping and analysis the optimal criterion for it. The derived optimal criterion has a similar form with signal to noise plus interference (SINR), with unassigned power included. Thus the unassigned power leads to an unpractical usage. We then investigate user's equivalent SINR for minimum mean square error (MMSE) detection serving as assignment criterion, and propose two kinds of user-grouping algorithms. In these algorithms, only partial channel information is needed at the base station, which saves a large part of bandwidth occupying by feedback information. The proposed algorithms are evaluated by computer simulations to be prior to the conventional algorithm at both BER performance and data rate. Meanwhile, they have a lower implementation complexity for practical reality.","PeriodicalId":331439,"journal":{"name":"2007 International Symposium on Communications and Information Technologies","volume":"203 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122415188","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 : 2007-12-04DOI: 10.1109/ISCIT.2007.4392194
P. Silva, R. Dinis
In this paper we consider the uplink transmission in MC-CDMA (multicarrier -coded division multiple access) systems. Since MC-CDMA signals are OFDM-like multicarrier signals, they have high envelope fluctuations and a high PMEPR (Peak-to-Mean Envelope Power Ratio) which leads to amplification difficulties. To reduce the envelope fluctuations of the transmitted signals, while maintaining the spectral efficiency, the MC-CDMA signal associated to each MT (mobile terminal) is submitted to a clipping device, followed by a frequency-domain filtering operation. However, the nonlinear distortion effects can be high when an MC-CDMA transmitter with reduced envelope fluctuations is intended. In this paper, we define an iterative receiver that jointly performs a turbo-MUD (Multiuser Detection) and the estimation and cancellation of the nonlinear distortion effects. The set of simulation results presented shows that the proposed receiver structure allows good performances, very close to the linear receiver ones, even for high system load and/or when a low-PMEPR is intended for each MT.
{"title":"Turbo multiuser detection for MC-CDMA signals with strongly nonlinear transmitters","authors":"P. Silva, R. Dinis","doi":"10.1109/ISCIT.2007.4392194","DOIUrl":"https://doi.org/10.1109/ISCIT.2007.4392194","url":null,"abstract":"In this paper we consider the uplink transmission in MC-CDMA (multicarrier -coded division multiple access) systems. Since MC-CDMA signals are OFDM-like multicarrier signals, they have high envelope fluctuations and a high PMEPR (Peak-to-Mean Envelope Power Ratio) which leads to amplification difficulties. To reduce the envelope fluctuations of the transmitted signals, while maintaining the spectral efficiency, the MC-CDMA signal associated to each MT (mobile terminal) is submitted to a clipping device, followed by a frequency-domain filtering operation. However, the nonlinear distortion effects can be high when an MC-CDMA transmitter with reduced envelope fluctuations is intended. In this paper, we define an iterative receiver that jointly performs a turbo-MUD (Multiuser Detection) and the estimation and cancellation of the nonlinear distortion effects. The set of simulation results presented shows that the proposed receiver structure allows good performances, very close to the linear receiver ones, even for high system load and/or when a low-PMEPR is intended for each MT.","PeriodicalId":331439,"journal":{"name":"2007 International Symposium on Communications and Information Technologies","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122598706","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 : 2007-12-04DOI: 10.1109/ISCIT.2007.4392018
T. Sato, S. Mizushima, S. Imai, Y. Suzuki, S. Murata
In this paper, a synchronous high-speed logic standard cells using bootstrapped technology for low temperature poly silicon thin film transistor -liquid crystal display (LTPS TFT-LCD) panel is proposed. The proposed TFT standard cells operate at high frequency region owing to the deep non-saturation operation by using the bootstrapped technology (BST). The proposed TFT standard cells can be reduced the pattern size by using the TFT capacitors for the bootstrapped capacitors. To confirm some characteristics of the proposed TFT standard cells, a full adder (FA) are simulated. As a result, the power delay products obtain about 1/5-9/10 times less value than that of the conventional standard cells using LTPS TFT.
{"title":"High speed standard cell using bootstrapped technology for LTPSTFT","authors":"T. Sato, S. Mizushima, S. Imai, Y. Suzuki, S. Murata","doi":"10.1109/ISCIT.2007.4392018","DOIUrl":"https://doi.org/10.1109/ISCIT.2007.4392018","url":null,"abstract":"In this paper, a synchronous high-speed logic standard cells using bootstrapped technology for low temperature poly silicon thin film transistor -liquid crystal display (LTPS TFT-LCD) panel is proposed. The proposed TFT standard cells operate at high frequency region owing to the deep non-saturation operation by using the bootstrapped technology (BST). The proposed TFT standard cells can be reduced the pattern size by using the TFT capacitors for the bootstrapped capacitors. To confirm some characteristics of the proposed TFT standard cells, a full adder (FA) are simulated. As a result, the power delay products obtain about 1/5-9/10 times less value than that of the conventional standard cells using LTPS TFT.","PeriodicalId":331439,"journal":{"name":"2007 International Symposium on Communications and Information Technologies","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127618869","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 : 2007-12-04DOI: 10.1109/ISCIT.2007.4392149
K. Asakura, H. Sanada, O. Ogurisu, M. Suzuki
In this paper, we propose a practical band estimation method for periodic superlattices by using semi-infinite periodic model, which is located in the middle of finite periodic model and infinite periodic model. According to the model proposed, we can estimate not only band structures but also ripples in passbands for periodic superlattices with simple calculation by applying image parameters in circuit theory. This model may be useful for energy filter designing, since the ripples in passbands are the essential information related with energy filter abilities.
{"title":"Practical band estimation for periodic superlattices by using semi-infinite periodic model","authors":"K. Asakura, H. Sanada, O. Ogurisu, M. Suzuki","doi":"10.1109/ISCIT.2007.4392149","DOIUrl":"https://doi.org/10.1109/ISCIT.2007.4392149","url":null,"abstract":"In this paper, we propose a practical band estimation method for periodic superlattices by using semi-infinite periodic model, which is located in the middle of finite periodic model and infinite periodic model. According to the model proposed, we can estimate not only band structures but also ripples in passbands for periodic superlattices with simple calculation by applying image parameters in circuit theory. This model may be useful for energy filter designing, since the ripples in passbands are the essential information related with energy filter abilities.","PeriodicalId":331439,"journal":{"name":"2007 International Symposium on Communications and Information Technologies","volume":"173 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133306942","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 : 2007-12-04DOI: 10.1109/ISCIT.2007.4392017
Yong Sun, F. Lai
Two topologies of SI comparator for low power current mode circuit implementation are presented. Employing different input stages, these two comparators are suitable to different application cases. Controlled by two complementary clock signals, the proposed comparator operates in a master and slave manner. Sharing a 0-static-power-dissipated dynamic latched comparator as the output comparators, both high power efficiency and high speed are acquired for these two comparators. Designed and simulated in TSMC 0.18 mum mixed signal CMOS technology with 1.8 V supply voltage, the proposed SI comparators achieve a current sensitivity up to 0.2 muA, and a sampling frequency up to 1 GHz, with 8.6 bits resolutions.
{"title":"Low power high speed switched current comparators for current mode ADC","authors":"Yong Sun, F. Lai","doi":"10.1109/ISCIT.2007.4392017","DOIUrl":"https://doi.org/10.1109/ISCIT.2007.4392017","url":null,"abstract":"Two topologies of SI comparator for low power current mode circuit implementation are presented. Employing different input stages, these two comparators are suitable to different application cases. Controlled by two complementary clock signals, the proposed comparator operates in a master and slave manner. Sharing a 0-static-power-dissipated dynamic latched comparator as the output comparators, both high power efficiency and high speed are acquired for these two comparators. Designed and simulated in TSMC 0.18 mum mixed signal CMOS technology with 1.8 V supply voltage, the proposed SI comparators achieve a current sensitivity up to 0.2 muA, and a sampling frequency up to 1 GHz, with 8.6 bits resolutions.","PeriodicalId":331439,"journal":{"name":"2007 International Symposium on Communications and Information Technologies","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133365877","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 : 2007-12-04DOI: 10.1109/ISCIT.2007.4392195
U. Gunawardana, K. Nguyen, R. Liyana-Pathirana
In this paper, we illustrate the use of importance sampling (IS) for efficient simulation of Turbo Codes over additive white Gaussian noise (AWGN) channels. In particular, we show how to bias the probability density function (pdf) of the AWGN process using the most probable error path (MPEP) method in order to maximize the computational efficiency gain. The new noise pdf is designed based on the optimal biased distribution where zero variance estimator can be achieved. It is demonstrated that the proposed method requires much smaller sample sizes to achieve the same accuracy required by a conventional MC estimator.
{"title":"Fast simulation of turbo codes over AWGN channels","authors":"U. Gunawardana, K. Nguyen, R. Liyana-Pathirana","doi":"10.1109/ISCIT.2007.4392195","DOIUrl":"https://doi.org/10.1109/ISCIT.2007.4392195","url":null,"abstract":"In this paper, we illustrate the use of importance sampling (IS) for efficient simulation of Turbo Codes over additive white Gaussian noise (AWGN) channels. In particular, we show how to bias the probability density function (pdf) of the AWGN process using the most probable error path (MPEP) method in order to maximize the computational efficiency gain. The new noise pdf is designed based on the optimal biased distribution where zero variance estimator can be achieved. It is demonstrated that the proposed method requires much smaller sample sizes to achieve the same accuracy required by a conventional MC estimator.","PeriodicalId":331439,"journal":{"name":"2007 International Symposium on Communications and Information Technologies","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115654243","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 : 2007-12-04DOI: 10.1109/ISCIT.2007.4392068
M. Saravanan, S. Ravi
Software radio development aims at wideband RF access and software partitioning for plug-and-play type of use. The development is facilitated by progress in silicon capabilities, silicon capabilities, signal processing power of new and future processors and reconfiguration methods (software download, smartcards, etc.). The future wireless and multimedia systems differ from old systems and from each other in terms of access methods, modulation, coding, etc. and they will also provide new type of services. This results in need for many product platforms unless we aren't able to design a common platform that could be programmed to different standards. The software radio is a good solution to this problem since it is reconfigurable to suit different standards at different continents. For this IS-95 CDMA technique is modified as a method of spread spectrum multiple access technique called frequency hopping/multiple carrier direct sequence-code division multiple access by Yang and Hanzo (2002) (FH/MC DS-CDMA). In this work, software defined radio (SDR) based FH/MC DS-CDMA transreceiver is proposed for future generation as well as existing generation Networks, which can carry multimedia applications at higher speed. Multiple carriers can be allotted as per user requirements with high secrecy and multiple encryptions. The performance analysis for the above scheme is shown supportive in terms of BER, power requirements, complexity, etc.
{"title":"SDR based multiple access technique for multimedia applications","authors":"M. Saravanan, S. Ravi","doi":"10.1109/ISCIT.2007.4392068","DOIUrl":"https://doi.org/10.1109/ISCIT.2007.4392068","url":null,"abstract":"Software radio development aims at wideband RF access and software partitioning for plug-and-play type of use. The development is facilitated by progress in silicon capabilities, silicon capabilities, signal processing power of new and future processors and reconfiguration methods (software download, smartcards, etc.). The future wireless and multimedia systems differ from old systems and from each other in terms of access methods, modulation, coding, etc. and they will also provide new type of services. This results in need for many product platforms unless we aren't able to design a common platform that could be programmed to different standards. The software radio is a good solution to this problem since it is reconfigurable to suit different standards at different continents. For this IS-95 CDMA technique is modified as a method of spread spectrum multiple access technique called frequency hopping/multiple carrier direct sequence-code division multiple access by Yang and Hanzo (2002) (FH/MC DS-CDMA). In this work, software defined radio (SDR) based FH/MC DS-CDMA transreceiver is proposed for future generation as well as existing generation Networks, which can carry multimedia applications at higher speed. Multiple carriers can be allotted as per user requirements with high secrecy and multiple encryptions. The performance analysis for the above scheme is shown supportive in terms of BER, power requirements, complexity, etc.","PeriodicalId":331439,"journal":{"name":"2007 International Symposium on Communications and Information Technologies","volume":"23 6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114163694","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 : 2007-12-04DOI: 10.1109/ISCIT.2007.4392022
H. H. Kha, H. Tuan, T.Q. Nguyen
This paper proposes a computationally efficient method for designing a class of triplet halfband filter banks. We show that the design of perfect reconstruction two-channel Alter banks with arbitrary regularity order can be precisely formulated as a semi-definite programming problem. We also show that the dual problem has a significant smaller number of variables and, hence, can be solved efficiently. The effectiveness of the proposed method is demonstrated by the design examples of filter banks with high filter order and arbitrary regularity order.
{"title":"Optimal design of triplet halfband filter banks via Semidefinite Programming","authors":"H. H. Kha, H. Tuan, T.Q. Nguyen","doi":"10.1109/ISCIT.2007.4392022","DOIUrl":"https://doi.org/10.1109/ISCIT.2007.4392022","url":null,"abstract":"This paper proposes a computationally efficient method for designing a class of triplet halfband filter banks. We show that the design of perfect reconstruction two-channel Alter banks with arbitrary regularity order can be precisely formulated as a semi-definite programming problem. We also show that the dual problem has a significant smaller number of variables and, hence, can be solved efficiently. The effectiveness of the proposed method is demonstrated by the design examples of filter banks with high filter order and arbitrary regularity order.","PeriodicalId":331439,"journal":{"name":"2007 International Symposium on Communications and Information Technologies","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114268499","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 : 2007-12-04DOI: 10.1109/ISCIT.2007.4392059
Tuo Liu, A. Mader, D. Staehle, D. Everitt
The UMTS enhanced uplink enables the efficient transport of packet-switched Internet traffic. With bit rates comparable to DSL links, it is expected that best-effort services like file-sharing become increasingly popular in UMTS networks. These services are often volume-based, which means that the sojourn time of a connection depends on the transmitted data volume. In this work, we propose an analytic model for the interference and capacity in the enhanced Uplink, which considers the impact of volume-based traffic on system capacity, other-cell interference and co-existing time-based QoS users. The analytic model is validated with a flow-level event-discrete simulation.
{"title":"Analytic modeling of the UMTS enhanced uplink in multi-cell environments with volume-based best-effort traffic","authors":"Tuo Liu, A. Mader, D. Staehle, D. Everitt","doi":"10.1109/ISCIT.2007.4392059","DOIUrl":"https://doi.org/10.1109/ISCIT.2007.4392059","url":null,"abstract":"The UMTS enhanced uplink enables the efficient transport of packet-switched Internet traffic. With bit rates comparable to DSL links, it is expected that best-effort services like file-sharing become increasingly popular in UMTS networks. These services are often volume-based, which means that the sojourn time of a connection depends on the transmitted data volume. In this work, we propose an analytic model for the interference and capacity in the enhanced Uplink, which considers the impact of volume-based traffic on system capacity, other-cell interference and co-existing time-based QoS users. The analytic model is validated with a flow-level event-discrete simulation.","PeriodicalId":331439,"journal":{"name":"2007 International Symposium on Communications and Information Technologies","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114611717","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 : 2007-12-04DOI: 10.1109/ISCIT.2007.4391999
S. Preradovic, I. Balbin, N. Karmakar
Development of a simple low-cost radio frequency identification (RFID) transponder for wireless sensor networks at 2.4 GHz is presented. The transponder is comprised of a rectangular patch antenna, RF modulating circuit and a low power mixed signal microcontroller from Texas Instruments. The transponder is powered by a 3 V pill-box battery and uses amplitude shift keying (ASK) backscatter modulation to communicate with a RFID reader. In this paper we present the design steps and measured results of the developed semi-passive RFID transponder.
{"title":"Development of a low-cost semi-passive transponder for sensor applications at 2.4GHz","authors":"S. Preradovic, I. Balbin, N. Karmakar","doi":"10.1109/ISCIT.2007.4391999","DOIUrl":"https://doi.org/10.1109/ISCIT.2007.4391999","url":null,"abstract":"Development of a simple low-cost radio frequency identification (RFID) transponder for wireless sensor networks at 2.4 GHz is presented. The transponder is comprised of a rectangular patch antenna, RF modulating circuit and a low power mixed signal microcontroller from Texas Instruments. The transponder is powered by a 3 V pill-box battery and uses amplitude shift keying (ASK) backscatter modulation to communicate with a RFID reader. In this paper we present the design steps and measured results of the developed semi-passive RFID transponder.","PeriodicalId":331439,"journal":{"name":"2007 International Symposium on Communications and Information Technologies","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114553695","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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