European Transactions on Telecommunications最新文献

{"title":"Energy consumption balancing (ECB) issues and mechanisms in wireless sensor networks (WSNs): a comprehensive overview","authors":"Farruh Ishmanov, A. Malik, S. Kim","doi":"10.1002/ett.1466","DOIUrl":"https://doi.org/10.1002/ett.1466","url":null,"abstract":"Wireless sensor networks comprise of a large number of low cost sensor nodes that have strictly restricted sensing, computation and communication capabilities. In addition to this, sensor nodes have limited battery life which is not rechargeable in many applications. Due to resource limitations for the sensor nodes, it is important to use energy efficiently for each sensor node. This will result in prolonged network lifetime and functionality. Energy consumption balancing (ECB) property ensures that the average energy dissipation per sensor is equal for all sensors in the network. ECB can be considered as energy efficiency property that optimally manages energy consumption of sensors to prolong network lifetime. This paper investigates the ECB theory and ECB related mechanisms. A classification of ECB mechanism is given by surveying the current and state of the art research in this area. In addition, comparison and main constraints of the mechanisms are presented. Copyright © 2011 John Wiley & Sons, Ltd. * Correspondence","PeriodicalId":50473,"journal":{"name":"European Transactions on Telecommunications","volume":"2 1","pages":"151-167"},"PeriodicalIF":0.0,"publicationDate":"2011-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74560430","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}

{"title":"On the security of an enhanced UMTS authentication and key agreement protocol","authors":"M. Hwang, Song-Kong Chong, Hsia-Hung Ou","doi":"10.1002/ett.1460","DOIUrl":"https://doi.org/10.1002/ett.1460","url":null,"abstract":"In this paper, we propose a practical and secure authentication and key agreement (AKA) scheme for Universal Mobile Telecommunications System (UMTS). The paper introduces a new requirement, ‘home network should be partially trusted in an authentication scheme’ to the UMTS. The scheme integrates symmetric and public key cryptosystem. Issues such as kinds of ‘subscriber identity/location confidential’ and ‘non-repudiation services’ are solved in the scheme. The paper provides computational analysis, messages transmission length analysis to the proposed scheme. Furthermore, comparisons with other schemes are also given. The results demonstrate that the proposed scheme is practical and secure. Copyright © 2010 John Wiley & Sons, Ltd.","PeriodicalId":50473,"journal":{"name":"European Transactions on Telecommunications","volume":"36 1","pages":"99-112"},"PeriodicalIF":0.0,"publicationDate":"2011-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79102778","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}

{"title":"OFDM channel estimation and data detection with superimposed pilots","authors":"T. Cui, C. Tellambura","doi":"10.1002/ett.1461","DOIUrl":"https://doi.org/10.1002/ett.1461","url":null,"abstract":"We propose three iterative superimposed-pilot based channel estimators for Orthogonal Frequency Division Multiplexing (OFDM) systems. Two are approximate maximum-likelihood, derived by using a Taylor expansion of the conditional probability density function of the received signal or by approximating the OFDM time signal as Gaussian, and one is minimum-mean square error. The complexity per iteration of these estimators is given by approximately O(NL^2), O(N^3) and O(NL), where N is the number of OFDM subcarriers and L is the channel length (time). Two direct (non-iterative) data detectors are also derived by averaging the log likelihood function over the channel statistics. These detectors require minimising the cost metric in an integer space, and we suggest the use of the sphere decoder for them. The Cramer–Rao bound for superimposed pilot based channel estimation is derived, and this bound is achieved by the proposed estimators. The optimal pilot placement is shown to be the equally spaced distribution of pilots. The bit error rate of the proposed estimators is simulated for N = 32 OFDM system. Our estimators perform fairly close to a separated training scheme, but without any loss of spectral efficiency.","PeriodicalId":50473,"journal":{"name":"European Transactions on Telecommunications","volume":"14 1","pages":"125-136"},"PeriodicalIF":0.0,"publicationDate":"2011-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85379453","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}

{"title":"Employing Volterra filters in the ADPCM technique for speech coding: a comprehensive investigation","authors":"G. Alipoor, M. Savoji","doi":"10.1002/ett.1440","DOIUrl":"https://doi.org/10.1002/ett.1440","url":null,"abstract":"Although linear filters are useful in a various applications in the context of speech processing, there are several evidences for existence of nonlinearity in speech signals. Our main aim is to launch a comprehensive investigation into the exploitation of nonlinear Volterra filters in the context of the ADPCM-based speech coding technique, using two methods of forward prediction, based on the LS criterion, and backward prediction, based on both LMS and RLS adaptation algorithms. In any case, after solving some innate problems, for example, ill-conditioning and instability, schemes for optimum exploitation of nonlinear prediction are developed and simulation results are provided, tested with several performance criteria. With forward prediction a scheme is developed to detect and flag those frames for which, after stabilizing, including the quadratic predictor is beneficial. Scalar and vector quantisation methods are used for quantising the residual signal and the filter parameters, respectively. The results show that using this scheme a negligible improvement (up to 0.62 dB in the SNR) can be achieved, in spite of the increase in bit rate and complexity. With backward prediction two frame-based schemes are developed in which for each frame, after examining a set of quadratic filters, the best filter in the sense of the best quality of the reconstructed speech is selected. The ultimate schemes result in an improvement of up to 1.5 dB in the overall SNR of the reconstructed speech at the cost of a slight increase in the bit-rate, a short delay and a demanding increase in the complexity. Copyright © 2010 John Wiley & Sons, Ltd.","PeriodicalId":50473,"journal":{"name":"European Transactions on Telecommunications","volume":"4 1","pages":"81-92"},"PeriodicalIF":0.0,"publicationDate":"2011-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86626296","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}

{"title":"Iterative MMSE estimation of SINR for turbo-coded FH-SS systems in partial-band interference and fading channels","authors":"Ahmad Gomaa, A. Elezabi","doi":"10.1002/ett.1452","DOIUrl":"https://doi.org/10.1002/ett.1452","url":null,"abstract":"The minimum mean square error (MMSE) estimate of the signal-to-interference-and-noise ratio (SINR) is derived for turbo-coded slow frequency hopping systems in the presence of partial-band interference and Rayleigh fading. The MMSE estimator operates without training symbols and iteratively uses the turbo decoder extrinsic information to improve the accuracy of the SINR estimate. Performance comparisons are made with a genie-aided MAP-based estimator and near-optimal performance is obtained for all but impractically small hop sizes. Copyright © 2010 John Wiley & Sons, Ltd.","PeriodicalId":50473,"journal":{"name":"European Transactions on Telecommunications","volume":"129 1","pages":"93-97"},"PeriodicalIF":0.0,"publicationDate":"2011-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75395423","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}

{"title":"ICI mitigation and diversity gain for OFDM systems in time-varying multipath fading channels","authors":"Shaoping Chen, Guangfa Dai, W. Rao","doi":"10.1002/ett.1458","DOIUrl":"https://doi.org/10.1002/ett.1458","url":null,"abstract":"In orthogonal frequency division multiplexing (OFDM) systems, channels' rapid variations cause intercarrier interference (ICI), resulting in performance degradation. Although ICI caused by channels' variations makes the reliable signal detection difficult, it also introduces Doppler diversity, which can be exploited to improve the system performance. In this paper, an ICI mitigation and Doppler-multipath diversity technique based on fractionally sampling at the receiver is proposed for OFDM systems over time-varying multipath fading channels. To reduce the computation burden of minimum mean-square error (MMSE) equaliser with successive detection (SD), an efficient algorithm is presented by using the property of matrix decomposition. The algorithm avoids direct or recursive computation of matrix inversion, thereby reducing the computation complexity and ensuring numerical stability. Simulations show that the proposed techniques can collect both Doppler and multipath diversity gains with moderate complexities. Copyright © 2010 John Wiley & Sons, Ltd.","PeriodicalId":50473,"journal":{"name":"European Transactions on Telecommunications","volume":"24 1","pages":"61-67"},"PeriodicalIF":0.0,"publicationDate":"2011-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85179874","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}

{"title":"Fast predicted handover in IEEE 802.16 networks","authors":"Zdenek Becvar, P. Mach","doi":"10.1002/ett.1445","DOIUrl":"https://doi.org/10.1002/ett.1445","url":null,"abstract":"The handover procedure can have a negative impact on the quality of service due to the short break in the connection. This paper proposes a modification of the hard handover procedure to enable reduction of the handover interruption time by exploiting the results of a handover prediction. The prediction of handover allows performing a part of handover procedure in advance to the interruption of a connection caused by the handover. The simulation results show that the proposed handover procedure fulfils requirements on the handover interruption according to the originating IEEE 802.16m standard for a wide range of frame durations. Moreover, the proposed technique outperforms conventional handover and all well-known proposals shortening the handover interruption as well. Copyright © 2010 John Wiley & Sons, Ltd.","PeriodicalId":50473,"journal":{"name":"European Transactions on Telecommunications","volume":"1 1","pages":"68-80"},"PeriodicalIF":0.0,"publicationDate":"2011-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82260851","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}

{"title":"Special Issue on European Wireless 2009 Conference","authors":"F. Fitzek, M. Katz","doi":"10.1002/ett.1457","DOIUrl":"https://doi.org/10.1002/ett.1457","url":null,"abstract":"This European Transactions on Communication is a special issue devoted to the European Wireless 2009 Conference. The technical contributions, originally selected for their quality and significance, where extended and reviewed before being included in this journal. Cooperation in wireless networks, a highly explored research area in recent years, is here present basically in all included papers. Research communities from academia and industry have spent countless efforts in investigating and developing cooperative networking concepts, due to the high potential of such technology. Indeed, benefits include significant performance improvements at link, network and system level. Moreover, efficiency in resource utilisation can also be enhanced by these techniques. Quite often, cooperation and cognition are used together, as in the cases of cognitive radio and networking. The application area of cooperation and cognition is wide, and in this issue the focus is mostly on exploiting these principles in the lower layers of the OSI stack, particularly PHY and MAC layers. The included papers cover a variety of important and highly relevant research issues, including cognitive radio, relaying techniques, network coding, dynamic resource allocation techniques, and in general, cooperative techniques applied to multicarrier systems. The first paper on this issue discusses methodological aspects of spectrum occupancy evaluation in cognitive radios. Dynamic spectrum allocation for cellular networks is considered in the second paper. An approach is proposed to derive the optimal allocation policies in terms of operator reward following optimal, heuristic and Qlearning methodologies. The third paper on this issue studies soft frequency reuse and dynamic subcarrier assignments in cellular OFDMA networks. The performance of the soft frequency reuse technique is investigated as a function of the power profiles of the frequency reuse patterns. The fourth paper proposes the use of cooperative feedback in multiuser diversity systems to improve both capacity and error rate. The considered approach efficiently avoids resource allocation errors, resulting in improved link and network performance. The fifth paper investigates the use of network coding in wireless cooperative local clusters for filesharing applications. The sixth paper shows for the very first time a practical implementation of network coding on commercial mobile phones together with practical measurements on supported data rate and energy consumption. The seventh paper on this special issue deals with persistent resource allocations for VoIP traffic in packetswitching mobile cellular networks. This paper studies the problem of efficient transmission of VoIP in a packetswitched network with dominant data traffic. An opensource system level simulation platform for IMTAdvanced systems is presented on the eighth paper. The platform allows studying dynamic protocol behaviour in multicellular mobile radio network ","PeriodicalId":50473,"journal":{"name":"European Transactions on Telecommunications","volume":"126 3 1","pages":"679"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83994050","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}

{"title":"A mobile application prototype using network coding","authors":"M. Pedersen, J. Heide, F. Fitzek, T. Larsen","doi":"10.1002/ett.1448","DOIUrl":"https://doi.org/10.1002/ett.1448","url":null,"abstract":"This paper looks into implementation details of network coding for a mobile application running on commercial mobile phones. We describe the necessary coding operations and algorithms that implements them. The coding algorithms forms the basis for a implementation in C++ and Symbian C++. We report on practical measurement results of coding throughput and energy consumption for a single-source multiple-sinks network, with and without recoding at the sinks. These results confirm that network coding is practical even on computationally weak platforms, and that network coding potentially can be used to reduce energy consumption. Copyright © 2010 John Wiley & Sons, Ltd.","PeriodicalId":50473,"journal":{"name":"European Transactions on Telecommunications","volume":"440 1","pages":"738-749"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79303839","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}

{"title":"Relaying results for indoor coverage in long-term evolution and beyond","authors":"V. Venkatkumar, T. Haustein, M. Faulkner","doi":"10.1002/ett.1450","DOIUrl":"https://doi.org/10.1002/ett.1450","url":null,"abstract":"Future cellular networks aim to improve the data rate to users in office and residential buildings. Wireless relaying is one of the possible solutions. In this approach, a relay is placed inside a building to get around the building penetration path loss. Decode and forward operation is employed for full re-use of the licensed bandwidth with frequency dependent link adaptation. In this paper, we report indoor measurement results using state of the art macrocellular and relay. Orthogonal frequency division duplexing (OFDM) and multiple input multiple output (MIMO) are used in both links. The relay measurements were performed for a single cell three terminal relay network setup. Results show that (a) relay provides better data rate and coverage as compared to macro and (b) feedback can further improve relay coverage. A relay is able to deliver data rate exceeding 40 Mbps to locations well inside the building. Copyright © 2010 John Wiley & Sons, Ltd.","PeriodicalId":50473,"journal":{"name":"European Transactions on Telecommunications","volume":"11 1","pages":"770-779"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81924736","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}