Optimizing the performance of adaptive modulation and coding (AMC) in practice has proven challenging. Prior research has struggled to find link quality metrics that are suitable for look-up-tables and simultaneously provide an injective mapping to error rate in wireless links that feature selective channels with hardware nonlinearities and non-Gaussian noise effects. This paper proposes a novel online support vector machine algorithm, compatible with accurate multidimensional link quality metrics, that is able to optimize AMC to the unique (potentially dynamic) hardware characteristics of each wireless device in selective channels. IEEE 802.11n simulations show that our proposed algorithm allows each individual wireless device to optimize the operating point in the rate/reliability tradeoff through frame-by-frame error evaluation. These simulations also show that our algorithm displays identical performance to alternative online AMC algorithms while drastically reducing complexity.
{"title":"Online adaptive modulation and coding with support vector machines","authors":"R. Daniels, R. Heath","doi":"10.1109/EW.2010.5483527","DOIUrl":"https://doi.org/10.1109/EW.2010.5483527","url":null,"abstract":"Optimizing the performance of adaptive modulation and coding (AMC) in practice has proven challenging. Prior research has struggled to find link quality metrics that are suitable for look-up-tables and simultaneously provide an injective mapping to error rate in wireless links that feature selective channels with hardware nonlinearities and non-Gaussian noise effects. This paper proposes a novel online support vector machine algorithm, compatible with accurate multidimensional link quality metrics, that is able to optimize AMC to the unique (potentially dynamic) hardware characteristics of each wireless device in selective channels. IEEE 802.11n simulations show that our proposed algorithm allows each individual wireless device to optimize the operating point in the rate/reliability tradeoff through frame-by-frame error evaluation. These simulations also show that our algorithm displays identical performance to alternative online AMC algorithms while drastically reducing complexity.","PeriodicalId":232165,"journal":{"name":"2010 European Wireless Conference (EW)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127844762","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}
Fourth generation (4G) and beyond-4G wireless standards must support sub-1Gbps data rates with peak bandwidth efficiencies of up to 30 bit/s/Hz. It is widely recognized that the use of multiple antennas on both ends of the wireless link, commonly referred to as MIMO, is the technology that will make this a reality. The problem is that most existing MIMO algorithms are either too complex to be able to support such rates or do not lend themselves to a parallel implementation, a must-have feature that will enable the use of low-power multi-core processors. In this paper we propose a parallel architecture and associated algorithm that has reasonable complexity. Most importantly, the algorithm possesses a performance-on-demand feature that allows for complexity, performance and power consumption to be traded off on a packet-by-packet basis.
{"title":"Parallel low-complexity MIMO detection algorithm using QR decomposition and Alamouti space-time code","authors":"Maher Arar, A. Yongaçoğlu","doi":"10.1109/EW.2010.5483405","DOIUrl":"https://doi.org/10.1109/EW.2010.5483405","url":null,"abstract":"Fourth generation (4G) and beyond-4G wireless standards must support sub-1Gbps data rates with peak bandwidth efficiencies of up to 30 bit/s/Hz. It is widely recognized that the use of multiple antennas on both ends of the wireless link, commonly referred to as MIMO, is the technology that will make this a reality. The problem is that most existing MIMO algorithms are either too complex to be able to support such rates or do not lend themselves to a parallel implementation, a must-have feature that will enable the use of low-power multi-core processors. In this paper we propose a parallel architecture and associated algorithm that has reasonable complexity. Most importantly, the algorithm possesses a performance-on-demand feature that allows for complexity, performance and power consumption to be traded off on a packet-by-packet basis.","PeriodicalId":232165,"journal":{"name":"2010 European Wireless Conference (EW)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122661672","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}
V. Tykhomyrov, A. Sayenko, O. Puchko, T. Hämäläinen
One of the key performance bottlenecks of existent 802.16 systems is the downlink signalling overhead. It is caused by the MAP messages that carry information on the data burst allocations. To decrease the MAP overhead, the 802.16 standard proposes a few mechanisms, such as the compressed MAP and sub-MAPs. However, similarly to the scheduling discipline, an exact algorithm to construct sub-MAPs is not specified and is left open for alternative implementations. In this paper, we study 802.16 sub-MAPs and propose an algorithm to construct an optimal sub-MAP configuration for the given burst allocations. We show that sub-MAPs can improve the system performance by almost 25%.
{"title":"Decreasing the MAP overhead in the IEEE 802.16 OFDMA system","authors":"V. Tykhomyrov, A. Sayenko, O. Puchko, T. Hämäläinen","doi":"10.1109/EW.2010.5483393","DOIUrl":"https://doi.org/10.1109/EW.2010.5483393","url":null,"abstract":"One of the key performance bottlenecks of existent 802.16 systems is the downlink signalling overhead. It is caused by the MAP messages that carry information on the data burst allocations. To decrease the MAP overhead, the 802.16 standard proposes a few mechanisms, such as the compressed MAP and sub-MAPs. However, similarly to the scheduling discipline, an exact algorithm to construct sub-MAPs is not specified and is left open for alternative implementations. In this paper, we study 802.16 sub-MAPs and propose an algorithm to construct an optimal sub-MAP configuration for the given burst allocations. We show that sub-MAPs can improve the system performance by almost 25%.","PeriodicalId":232165,"journal":{"name":"2010 European Wireless Conference (EW)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115460432","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}
In FBMC transmission systems, the bit rate is maximized when OQAM modulation is employed. One of the characteristics of this modulation is that the received data symbols are accompanied by interference terms, which complicates the application of ML techniques in optimal decoders. Two approaches are proposed to cope with this situation. The first one exploits the MMSE estimation of the interference terms and it introduces no additional delay. In the second one, the interference terms are calculated from past, present and future data symbols, either already decided or estimated. The gains provided by these approaches, with respect to MMSE, are assessed and illustrated by simulation.
{"title":"Maximum likelihood detection in spatial multiplexing with FBMC","authors":"R. Zakaria, D. L. Ruyet, M. Bellanger","doi":"10.1109/EW.2010.5483520","DOIUrl":"https://doi.org/10.1109/EW.2010.5483520","url":null,"abstract":"In FBMC transmission systems, the bit rate is maximized when OQAM modulation is employed. One of the characteristics of this modulation is that the received data symbols are accompanied by interference terms, which complicates the application of ML techniques in optimal decoders. Two approaches are proposed to cope with this situation. The first one exploits the MMSE estimation of the interference terms and it introduces no additional delay. In the second one, the interference terms are calculated from past, present and future data symbols, either already decided or estimated. The gains provided by these approaches, with respect to MMSE, are assessed and illustrated by simulation.","PeriodicalId":232165,"journal":{"name":"2010 European Wireless Conference (EW)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131937482","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 target of the paper is to study performance of high speed uplink packet access (HSUPA) in indoor environment, applicability of uplink diversity reception for HSUPA, and to provide guidelines for HSUPA coverage planning indoor environment. The single-user measurements show that with the tested antenna configuration without diversity, maximum practical throughput varies between 1.4 and 1.6 Mbps, and it can be achieved when pilot coverage is above -95 dBm. HSUPA was also measured with spatial and polarization diversity reception, and they were noticed to provide about 4.5 dB improvement in uplink reception, providing 20-40 % improvement in HSUPA throughput with pilot coverage below -95 dBm. Diversity reception can provide provide modest gain in system performance, but with planning threshold RSCP > -95 dBm, almost the same performance can be achieved without diversity antennas.
{"title":"Measurements on HSUPA with uplink diversity reception in indoor environment","authors":"T. Isotalo, Jukka Lempiäinen","doi":"10.1109/EW.2010.5483483","DOIUrl":"https://doi.org/10.1109/EW.2010.5483483","url":null,"abstract":"The target of the paper is to study performance of high speed uplink packet access (HSUPA) in indoor environment, applicability of uplink diversity reception for HSUPA, and to provide guidelines for HSUPA coverage planning indoor environment. The single-user measurements show that with the tested antenna configuration without diversity, maximum practical throughput varies between 1.4 and 1.6 Mbps, and it can be achieved when pilot coverage is above -95 dBm. HSUPA was also measured with spatial and polarization diversity reception, and they were noticed to provide about 4.5 dB improvement in uplink reception, providing 20-40 % improvement in HSUPA throughput with pilot coverage below -95 dBm. Diversity reception can provide provide modest gain in system performance, but with planning threshold RSCP > -95 dBm, almost the same performance can be achieved without diversity antennas.","PeriodicalId":232165,"journal":{"name":"2010 European Wireless Conference (EW)","volume":"11 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131027587","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}
Long Term Evolution represents an emerging and promising technology for providing a broadband ubiquitous Internet access. But several aspects have to be considered in order to provide an effective service to users. In particular, in this work, we consider the problem of optimizing the performance of real time downlink communications using a novel two-level scheduling algorithm. The upper level exploits an innovative approach based on discrete-time linear control theory. At the lower level, instead, a maximum throughput scheduler has been properly tailored to our purposes. The performance and the complexity of the proposed scheme have been evaluated theoretically and by using simulations. Both the analyses demonstrate the effectiveness of the proposed approach.
{"title":"A two-level scheduling algorithm for QoS support in the downlink of LTE cellular networks","authors":"G. Piro, L. Grieco, G. Boggia, P. Camarda","doi":"10.1109/EW.2010.5483423","DOIUrl":"https://doi.org/10.1109/EW.2010.5483423","url":null,"abstract":"Long Term Evolution represents an emerging and promising technology for providing a broadband ubiquitous Internet access. But several aspects have to be considered in order to provide an effective service to users. In particular, in this work, we consider the problem of optimizing the performance of real time downlink communications using a novel two-level scheduling algorithm. The upper level exploits an innovative approach based on discrete-time linear control theory. At the lower level, instead, a maximum throughput scheduler has been properly tailored to our purposes. The performance and the complexity of the proposed scheme have been evaluated theoretically and by using simulations. Both the analyses demonstrate the effectiveness of the proposed approach.","PeriodicalId":232165,"journal":{"name":"2010 European Wireless Conference (EW)","volume":"64 12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127061051","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}
K. Dufková, M. Bjelica, B. Moon, L. Kencl, J. Le Boudec
We present a concrete methodology for saving energy in future and contemporary cellular networks. It is based on re-arranging the user-cell association so as to allow shutting down under-utilized parts of the network. We consider a hypothetical static case where we have complete knowledge of stationary user locations and thus the results represent an upper bound of potential energy savings. We formulate the problem as a binary integer programming problem, thus it is NP-hard, and we present a heuristic approximation method. We simulate the methodology on an example real cellular network topology with traffic-and user distribution generated according to recently measured patterns. Further, we evaluate the energy savings, using realistic energy profiles, and the impact on the user-perceived network performance, represented by delay and throughput, at various times of day. The general findings conclude that up to 50% energy may be saved in less busy periods, while the performance effects remain limited. We conclude that practical, real-time user-cell re-allocation methodology, taking into account user mobility predictions, may thus be feasible and bring significant energy savings at acceptable performance impact.
{"title":"Energy savings for cellular network with evaluation of impact on data traffic performance","authors":"K. Dufková, M. Bjelica, B. Moon, L. Kencl, J. Le Boudec","doi":"10.1109/EW.2010.5483431","DOIUrl":"https://doi.org/10.1109/EW.2010.5483431","url":null,"abstract":"We present a concrete methodology for saving energy in future and contemporary cellular networks. It is based on re-arranging the user-cell association so as to allow shutting down under-utilized parts of the network. We consider a hypothetical static case where we have complete knowledge of stationary user locations and thus the results represent an upper bound of potential energy savings. We formulate the problem as a binary integer programming problem, thus it is NP-hard, and we present a heuristic approximation method. We simulate the methodology on an example real cellular network topology with traffic-and user distribution generated according to recently measured patterns. Further, we evaluate the energy savings, using realistic energy profiles, and the impact on the user-perceived network performance, represented by delay and throughput, at various times of day. The general findings conclude that up to 50% energy may be saved in less busy periods, while the performance effects remain limited. We conclude that practical, real-time user-cell re-allocation methodology, taking into account user mobility predictions, may thus be feasible and bring significant energy savings at acceptable performance impact.","PeriodicalId":232165,"journal":{"name":"2010 European Wireless Conference (EW)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127042250","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}
M. Deruyck, W. Vereecken, E. Tanghe, W. Joseph, M. Pickavet, L. Martens, P. Demeester
The power consumption of wireless access networks will become an important issue in the coming years. In this paper the power consumption of base stations for mobile WiMAX, fixed WiMAX and UMTS is modelled. This power consumption is evaluated in relation to the coverage. For a physical bit rate of 2 Mbps, a power consumption of approximately 5600 W and a range of 1 km is obtained with UMTS. Fixed WiMAX covers 70 % and mobile WiMAX only 40 % of this range. However, fixed and mobile WiMAX consume roughly 50 % less than UMTS. In a suburban area and for a physical bitrate of 2 Mbps, fixed WiMAX base stations consume approximately 6 W per user, mobile WiMAX base stations 17 W per user, and UMTS base stations 5 W per user. The power consumption of these wireless access networks is compared with other access network technologies and research challenges concerning these access networks are presented.
{"title":"Power consumption in wireless access network","authors":"M. Deruyck, W. Vereecken, E. Tanghe, W. Joseph, M. Pickavet, L. Martens, P. Demeester","doi":"10.1109/EW.2010.5483506","DOIUrl":"https://doi.org/10.1109/EW.2010.5483506","url":null,"abstract":"The power consumption of wireless access networks will become an important issue in the coming years. In this paper the power consumption of base stations for mobile WiMAX, fixed WiMAX and UMTS is modelled. This power consumption is evaluated in relation to the coverage. For a physical bit rate of 2 Mbps, a power consumption of approximately 5600 W and a range of 1 km is obtained with UMTS. Fixed WiMAX covers 70 % and mobile WiMAX only 40 % of this range. However, fixed and mobile WiMAX consume roughly 50 % less than UMTS. In a suburban area and for a physical bitrate of 2 Mbps, fixed WiMAX base stations consume approximately 6 W per user, mobile WiMAX base stations 17 W per user, and UMTS base stations 5 W per user. The power consumption of these wireless access networks is compared with other access network technologies and research challenges concerning these access networks are presented.","PeriodicalId":232165,"journal":{"name":"2010 European Wireless Conference (EW)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116051991","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}
In this paper we present a solution for the realization of large Cognitive Radio Networks. The solution features a spectrum-aware neighbor discovery and clustering scheme that works in conjunction with a network coded cognitive control channel in order to allow Cognitive Radio devices to opportunistically access the unused spectrum. We evaluate the performance of the proposed solution with respect to the characteristics of the formed clusters as well as the reliability of the dissemination of the control information within the cluster.
{"title":"A cluster formation protocol for cognitive radio ad hoc networks","authors":"Alfred Asterjadhi, N. Baldo, M. Zorzi","doi":"10.1109/EW.2010.5483442","DOIUrl":"https://doi.org/10.1109/EW.2010.5483442","url":null,"abstract":"In this paper we present a solution for the realization of large Cognitive Radio Networks. The solution features a spectrum-aware neighbor discovery and clustering scheme that works in conjunction with a network coded cognitive control channel in order to allow Cognitive Radio devices to opportunistically access the unused spectrum. We evaluate the performance of the proposed solution with respect to the characteristics of the formed clusters as well as the reliability of the dissemination of the control information within the cluster.","PeriodicalId":232165,"journal":{"name":"2010 European Wireless Conference (EW)","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123595370","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}
Femtocell concept is gaining popularity as a promising way to improve resource reuse and thereby system capacity. This paper addresses a co-existence scenario where outdoor macrocell users and indoor femtocell users are located in close proximity. Impact of macro- and femtocells originated co-channel interference to the desired femto- and macrocell uplink is evaluated by means of outage probability and achievable throughput, varying key system parameters. The numerical results show that the desired femtolink is robust against interference. It is interfered almost equally by other femtocells and by the macrocell whereas the desired macrolink is mainly constrained by interference from other macrocell links.
{"title":"Co-channel co-existence study of outdoor macrocell and indoor femtocell users","authors":"P. Pirinen","doi":"10.1109/EW.2010.5483420","DOIUrl":"https://doi.org/10.1109/EW.2010.5483420","url":null,"abstract":"Femtocell concept is gaining popularity as a promising way to improve resource reuse and thereby system capacity. This paper addresses a co-existence scenario where outdoor macrocell users and indoor femtocell users are located in close proximity. Impact of macro- and femtocells originated co-channel interference to the desired femto- and macrocell uplink is evaluated by means of outage probability and achievable throughput, varying key system parameters. The numerical results show that the desired femtolink is robust against interference. It is interfered almost equally by other femtocells and by the macrocell whereas the desired macrolink is mainly constrained by interference from other macrocell links.","PeriodicalId":232165,"journal":{"name":"2010 European Wireless Conference (EW)","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121257249","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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