In this paper we focus on adaptive modulation strategies for multicast service in orthogonal frequency division multiple access systems. A reward function has been defined as the optimization target, which includes both the average user throughput and bit error rate. We also developed an adaptive modulation strategy, namely local best reward strategy, to maximize this reward function. The performance of different modulation strategies are compared in different SNR distribution scenarios, and the optimum strategy in each scenario is suggested.
{"title":"Adaptive Modulation for a Downlink Multicast Channel in OFDMA systems","authors":"Haibo Wang, H. Schwefel, T. Toftegaard","doi":"10.1109/WCNC.2008.284","DOIUrl":"https://doi.org/10.1109/WCNC.2008.284","url":null,"abstract":"In this paper we focus on adaptive modulation strategies for multicast service in orthogonal frequency division multiple access systems. A reward function has been defined as the optimization target, which includes both the average user throughput and bit error rate. We also developed an adaptive modulation strategy, namely local best reward strategy, to maximize this reward function. The performance of different modulation strategies are compared in different SNR distribution scenarios, and the optimum strategy in each scenario is suggested.","PeriodicalId":292621,"journal":{"name":"2007 IEEE Wireless Communications and Networking Conference","volume":"199 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133824310","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}
Kari Aho, T. Ristaniemi, J. Kurjenniemi, V. Haikola
The aim of this paper is to evaluate the system level performance of multimedia broadcast multicast service (MBMS) in WCDMA networks. To enhance coverage and data rates of MBMS users, two macro diversity concepts were introduced in 3GPP release 6: soft and selective combining. Prior work on the evaluation of MBMS with macro diversity schemes has been restricted to link level studies or to very limited scenarios in system level studies. This paper examines the concepts in more detail with dynamic system level tool in which e.g. mobility of users and interactions of the radio resource management functionalities are explicitly taken into account. The evaluation of combining set size and data rates with different thresholds and delays in the combining procedures are especially emphasized. Considering point-to-multipoint (p-t-m) mode of MBMS, the studies indicated clear performance improvements to be gained with macro diversity. In addition, the impact of delays in combining set update procedures was observed to be rather small.
{"title":"System Level Performance of Multimedia Broadcast Multicast Service (MBMS) with Macro Diversity","authors":"Kari Aho, T. Ristaniemi, J. Kurjenniemi, V. Haikola","doi":"10.1109/WCNC.2007.612","DOIUrl":"https://doi.org/10.1109/WCNC.2007.612","url":null,"abstract":"The aim of this paper is to evaluate the system level performance of multimedia broadcast multicast service (MBMS) in WCDMA networks. To enhance coverage and data rates of MBMS users, two macro diversity concepts were introduced in 3GPP release 6: soft and selective combining. Prior work on the evaluation of MBMS with macro diversity schemes has been restricted to link level studies or to very limited scenarios in system level studies. This paper examines the concepts in more detail with dynamic system level tool in which e.g. mobility of users and interactions of the radio resource management functionalities are explicitly taken into account. The evaluation of combining set size and data rates with different thresholds and delays in the combining procedures are especially emphasized. Considering point-to-multipoint (p-t-m) mode of MBMS, the studies indicated clear performance improvements to be gained with macro diversity. In addition, the impact of delays in combining set update procedures was observed to be rather small.","PeriodicalId":292621,"journal":{"name":"2007 IEEE Wireless Communications and Networking Conference","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125236761","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}
Yang Xiao, Michael Nolen, Xiaojiang Du, Jingyuan Zhang
In this paper, we provide a simulation of MPEG-4 using OPNET over the IEEE 802.11 wireless local area networks (WLANs) in terms of throughput and impacts of multiple MPEG-4 streams and compression rates on the throughput. Simulation results are explained in detail, especially for MPEG-4 simulations. Our results show that a higher throughput does not always mean a better quality of MPEG-4 video.
{"title":"Simulating MPEG-4 over the IEEE 802.11 WLANs","authors":"Yang Xiao, Michael Nolen, Xiaojiang Du, Jingyuan Zhang","doi":"10.1109/WCNC.2007.494","DOIUrl":"https://doi.org/10.1109/WCNC.2007.494","url":null,"abstract":"In this paper, we provide a simulation of MPEG-4 using OPNET over the IEEE 802.11 wireless local area networks (WLANs) in terms of throughput and impacts of multiple MPEG-4 streams and compression rates on the throughput. Simulation results are explained in detail, especially for MPEG-4 simulations. Our results show that a higher throughput does not always mean a better quality of MPEG-4 video.","PeriodicalId":292621,"journal":{"name":"2007 IEEE Wireless Communications and Networking Conference","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124578991","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}
How to prolong the lifetime of wireless sensor networks is an important issue in designing environmental monitoring applications. In this paper, we propose a novel energy-efficient data gathering algorithm, called EDP, which is based on dual prediction. Both sensor nodes and the sink node use the same prediction algorithm based on the same historical data. Each sensor node predicts the values of the data to be sensed according to its recorded historical information. When getting the sensory data, the node compares it with the predicted data. Only when the difference between the predicted and the sensed data values exceeds a pre-defined threshold, the sensor node sends the newly sensed data to the sink node. For the sink node, during a reporting period, if it receives data from a sensor node, the received data will be used as the "sensed data"; otherwise, the sink node will use the prediction algorithm to get the "predicted value" in the same way as the sensor node does. Theoretical analysis and simulation studies show that EDP can greatly reduce the amount of data transmitted in the network, leading to significant energy saving on the sensor nodes and extension of the lifetime of the entire network.
{"title":"Energy-Efficient Dual Prediction-Based Data Gathering for Environmental Monitoring Applications","authors":"Guojun Wang, Huan Wang, Jiannong Cao, M. Guo","doi":"10.1109/WCNC.2007.644","DOIUrl":"https://doi.org/10.1109/WCNC.2007.644","url":null,"abstract":"How to prolong the lifetime of wireless sensor networks is an important issue in designing environmental monitoring applications. In this paper, we propose a novel energy-efficient data gathering algorithm, called EDP, which is based on dual prediction. Both sensor nodes and the sink node use the same prediction algorithm based on the same historical data. Each sensor node predicts the values of the data to be sensed according to its recorded historical information. When getting the sensory data, the node compares it with the predicted data. Only when the difference between the predicted and the sensed data values exceeds a pre-defined threshold, the sensor node sends the newly sensed data to the sink node. For the sink node, during a reporting period, if it receives data from a sensor node, the received data will be used as the \"sensed data\"; otherwise, the sink node will use the prediction algorithm to get the \"predicted value\" in the same way as the sensor node does. Theoretical analysis and simulation studies show that EDP can greatly reduce the amount of data transmitted in the network, leading to significant energy saving on the sensor nodes and extension of the lifetime of the entire network.","PeriodicalId":292621,"journal":{"name":"2007 IEEE Wireless Communications and Networking Conference","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132013988","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}
The work reported in this paper serves two purposes. First, an alternative comprehensive approach is proposed for the understanding of the mechanism behind QPSK. This focuses on how a QPSK modulator decides to represent each pair of to be transmitted bits by which of its four possible phase shifts. This approach is based entirely on the analysis of phasors and is completely mathematical-less. The second part of this work proposes a method by which complex modulation schemes, like QPSK, can be implemented using only first degree components in Simulink, avoiding all the hurdles of mathematically-complicated blocks. The implementation, in the second part, confirms the viability of the approach in the first part of this work. Results show that the data received on the other end of a noiseless channel exactly matches the data sent despite a slight unavoidable delay.
{"title":"A New Approach to QPSK: Mechanism and Implementation","authors":"A. Abuelmaatti, I. Thayne, Steve Beaumont","doi":"10.1109/WCNC.2007.446","DOIUrl":"https://doi.org/10.1109/WCNC.2007.446","url":null,"abstract":"The work reported in this paper serves two purposes. First, an alternative comprehensive approach is proposed for the understanding of the mechanism behind QPSK. This focuses on how a QPSK modulator decides to represent each pair of to be transmitted bits by which of its four possible phase shifts. This approach is based entirely on the analysis of phasors and is completely mathematical-less. The second part of this work proposes a method by which complex modulation schemes, like QPSK, can be implemented using only first degree components in Simulink, avoiding all the hurdles of mathematically-complicated blocks. The implementation, in the second part, confirms the viability of the approach in the first part of this work. Results show that the data received on the other end of a noiseless channel exactly matches the data sent despite a slight unavoidable delay.","PeriodicalId":292621,"journal":{"name":"2007 IEEE Wireless Communications and Networking Conference","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123426706","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}
This paper represents a method based on generalizing Delbrouck's algorithm for calculating the access capacities of multi-service time division duplex-code division multiple access (TDD-CDMA) networks. The method models the system as a multi-service model with state dependent soft blocking probabilities, and it uses the soft capacity limit caused by TDD-CDMA system in calculating the call blocking rate of multi-services. The traffic models used in this method are insensitive to the service time distribution and thus the method is very robust for applications. So it is more accurate than multi-dimensional Erlang-B formula, which does not consider the soft capacity, and it is also simpler than resolving the complex linear system equations with soft capacity. The paper provides both analytical results and simulation results to support the method, and these results match. Thus the proposed method can be used in TDD-CDMA network dimensioning and optimizing.
{"title":"Multi-Service Access Capacities Analysis of TDDCDMA System with Soft Blocking","authors":"Y. Qian, B. Fan, K. Zheng, Wenbo Wang","doi":"10.1109/WCNC.2007.569","DOIUrl":"https://doi.org/10.1109/WCNC.2007.569","url":null,"abstract":"This paper represents a method based on generalizing Delbrouck's algorithm for calculating the access capacities of multi-service time division duplex-code division multiple access (TDD-CDMA) networks. The method models the system as a multi-service model with state dependent soft blocking probabilities, and it uses the soft capacity limit caused by TDD-CDMA system in calculating the call blocking rate of multi-services. The traffic models used in this method are insensitive to the service time distribution and thus the method is very robust for applications. So it is more accurate than multi-dimensional Erlang-B formula, which does not consider the soft capacity, and it is also simpler than resolving the complex linear system equations with soft capacity. The paper provides both analytical results and simulation results to support the method, and these results match. Thus the proposed method can be used in TDD-CDMA network dimensioning and optimizing.","PeriodicalId":292621,"journal":{"name":"2007 IEEE Wireless Communications and Networking Conference","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128788001","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}
This review paper describes some of the practical problems frequently encountered when antennas are integrated with user devices such as handsets, laptop computers, wireless access points and earphones and suggest a range of solutions that have been shown to increase antenna efficiency.
{"title":"Embedding Antennas in User Equipments","authors":"B. Collins","doi":"10.1109/WCNC.2007.436","DOIUrl":"https://doi.org/10.1109/WCNC.2007.436","url":null,"abstract":"This review paper describes some of the practical problems frequently encountered when antennas are integrated with user devices such as handsets, laptop computers, wireless access points and earphones and suggest a range of solutions that have been shown to increase antenna efficiency.","PeriodicalId":292621,"journal":{"name":"2007 IEEE Wireless Communications and Networking Conference","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134550578","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}
Radio frequency identification (RFID) is a technology that recognizes information and circumference environment from tags attached to objects via wireless technology, and provides various services such as location tacking, supply chain management. The mobile RFID technology which uses this RFID technology gives mobility to the RFID leader and makes it possible to exchange information between the users and objects whenever or wherever it is needed. The KT introduced the portable Internet service (WiBro) into commercial service as a new growth engine. WiBro is the wireless Internet service which enables a high speed Internet even while moving. Based on WiBro, Korea Telecom (KT) is also developing a new concept WiBro RFID service, combining the WiBro network and the mobile RFID. In this paper, we introduce a mobile RFID service platform and some prototype services based on wireless broadband (WiBro) network.
{"title":"WiBro-Based Mobile RFID Service Development","authors":"Seok-Hyun Kim, Soonyong Song, Hyunsub Jung","doi":"10.1109/WCNC.2007.533","DOIUrl":"https://doi.org/10.1109/WCNC.2007.533","url":null,"abstract":"Radio frequency identification (RFID) is a technology that recognizes information and circumference environment from tags attached to objects via wireless technology, and provides various services such as location tacking, supply chain management. The mobile RFID technology which uses this RFID technology gives mobility to the RFID leader and makes it possible to exchange information between the users and objects whenever or wherever it is needed. The KT introduced the portable Internet service (WiBro) into commercial service as a new growth engine. WiBro is the wireless Internet service which enables a high speed Internet even while moving. Based on WiBro, Korea Telecom (KT) is also developing a new concept WiBro RFID service, combining the WiBro network and the mobile RFID. In this paper, we introduce a mobile RFID service platform and some prototype services based on wireless broadband (WiBro) network.","PeriodicalId":292621,"journal":{"name":"2007 IEEE Wireless Communications and Networking Conference","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123837958","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}
S. McBeath, J. Smith, D. Reed, Hao Bi, D. Pinckley, A. Rodriguez-Herrera, Jim O'Connor
Voice over Internet protocol (VoIP) will be commonplace in future wireless standards. Due to the potentially large number of VoIP users in a wireless system, the overhead associated with controlling VoIP transmissions can hinder system performance, unless it is carefully managed. This paper outlines current efforts in B3G (beyond 3G) standards development to efficiently control VoIP transmissions by grouping VoIP users into scheduling groups, assigning the group a set of shared time-frequency resources, and using bitmap signaling to allocate resources. System level simulations are used to validate the signaling technique and show that the technique can efficiently support 93 users per megahertz. Potential further improvements are described.
{"title":"Efficient Signaling for VoIP in OFDMA","authors":"S. McBeath, J. Smith, D. Reed, Hao Bi, D. Pinckley, A. Rodriguez-Herrera, Jim O'Connor","doi":"10.1109/WCNC.2007.420","DOIUrl":"https://doi.org/10.1109/WCNC.2007.420","url":null,"abstract":"Voice over Internet protocol (VoIP) will be commonplace in future wireless standards. Due to the potentially large number of VoIP users in a wireless system, the overhead associated with controlling VoIP transmissions can hinder system performance, unless it is carefully managed. This paper outlines current efforts in B3G (beyond 3G) standards development to efficiently control VoIP transmissions by grouping VoIP users into scheduling groups, assigning the group a set of shared time-frequency resources, and using bitmap signaling to allocate resources. System level simulations are used to validate the signaling technique and show that the technique can efficiently support 93 users per megahertz. Potential further improvements are described.","PeriodicalId":292621,"journal":{"name":"2007 IEEE Wireless Communications and Networking Conference","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129547328","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}
Shigang Tang, Ke Gong, Jun Wang, Kewu Peng, Changyong Pan, Zhixing Yang
As one of the most common linearization techniques, adaptive digital predistortion minimizes the difference between the input signal of the predistorter and the feedback signal from the power amplifier. The loop delay between these two signals must be controlled precisely so that the convergence of the predistorter should be assured. In this paper a novel two-stage loop delay correction scheme is presented. In the first stage, the integer delay between the input signal and the feedback signal is estimated based on the cross-correlation of them. In the second stage, the fractional delay between these two signals are corrected by a delay lock loop (DLL) circuit, in which a novel timing error detector used as the discriminator is proposed. The proposed loop delay correction scheme is applied to an adaptive digital predistorter in an orthogonal frequency-division multiplexing (OFDM) system. Simulation results show that the proposed loop delay correction method eliminates the loop delay perfectly, so that nearly optimal power spectral density (PSD) performance is achieved and a high degree of linearization is realized.
{"title":"Loop Delay Correction for Adaptive Digital Linearization of Power Amplifiers","authors":"Shigang Tang, Ke Gong, Jun Wang, Kewu Peng, Changyong Pan, Zhixing Yang","doi":"10.1109/WCNC.2007.372","DOIUrl":"https://doi.org/10.1109/WCNC.2007.372","url":null,"abstract":"As one of the most common linearization techniques, adaptive digital predistortion minimizes the difference between the input signal of the predistorter and the feedback signal from the power amplifier. The loop delay between these two signals must be controlled precisely so that the convergence of the predistorter should be assured. In this paper a novel two-stage loop delay correction scheme is presented. In the first stage, the integer delay between the input signal and the feedback signal is estimated based on the cross-correlation of them. In the second stage, the fractional delay between these two signals are corrected by a delay lock loop (DLL) circuit, in which a novel timing error detector used as the discriminator is proposed. The proposed loop delay correction scheme is applied to an adaptive digital predistorter in an orthogonal frequency-division multiplexing (OFDM) system. Simulation results show that the proposed loop delay correction method eliminates the loop delay perfectly, so that nearly optimal power spectral density (PSD) performance is achieved and a high degree of linearization is realized.","PeriodicalId":292621,"journal":{"name":"2007 IEEE Wireless Communications and Networking Conference","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116576159","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：