The Experts below are selected from a list of 370032 Experts worldwide ranked by ideXlab platform
Tao Chen - One of the best experts on this subject based on the ideXlab platform.
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Clustering concept using device-to-device communication in Cellular System
IEEE Wireless Communications and Networking Conference WCNC, 2010Co-Authors: Timo Koskela, Sami Hakola, Tao Chen, Janne LehtomakiAbstract:We study how direct communication within a group of devices, cluster, can improve the performance of a conventional Cellular System. The clusters are formed from devices that are close and communicating with each other, for example, sharing data. The clusters share the radio resources among other devices in the System thus creating a mixed network System comprising directly communicating devices and devices having radio links to and from the base stations. In this kind of a System the additional challenge is to decide when clusters shall use direct communication and when conventional Cellular radio links to communicate with each other. Here, in addition to clustering concept description we provide new means to analyse achievable System performance when clustering communication is integrated into a Cellular network and especially into an interference limited System.
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Effective interference cancellation scheme for device-to-device communication underlaying Cellular networks
IEEE Vehicular Technology Conference, 2010Co-Authors: Haiming Wang, Qing Huang, Tao Chen, Tao PengAbstract:It is expected that Device-to-Device (D2D) communication is allowed to underlay future Cellular networks such as IMT-Advanced for spectrum efficiency. However, by reusing the uplink spectrums with the Cellular System, the interference to D2D users has to be addressed to maximize the overall System performance. In this paper, a novel method to deal with the resource allocation and interference avoidance issues by utilizing the network peculiarity of a hybrid network to share the uplink resource is proposed and the implementation details are described in a real Cellular System. Simulation results prove that satisfying performance can be achieved by using the proposed mechanism.
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Device-to-device (D2D) communication in Cellular network - Performance analysis of optimum and practical communication mode selection
IEEE Wireless Communications and Networking Conference WCNC, 2010Co-Authors: Sami Hakola, Janne Lehtoma, Tao Chen, Timo KoskelaAbstract:In a Cellular network System one way to increase its capacity is to allow direct communication between closely located user devices when they are communicating with each other instead of conveying data from one device to the other via the radio and core network. The problem is then when the network shall assign direct communication mode and when not. In previous works the decision has been done individually per communicating device pair not taking into account other devices and the current state of the network. We derive means for getting optimal communication mode for all devices in the System in terms of System equations. The System equations capture information of the network such as link gains, noise levels, signal-to-interference-and-noise-ratios, etc., as well as communication mode selection for the devices. Using the derived equations performance bounds for the Cellular System where D2D communication is an additional communication mode are illustrated via simulations. Further, practical communication mode selection algorithms are used to evaluate their System performance against the achievable bounds. Analysis show the usability of the System equations and the potential of having D2D operation integrated into a Cellular System when there is enough local communication occurring.
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Time hopping for device-to-device communication in LTE Cellular System
IEEE Wireless Communications and Networking Conference WCNC, 2010Co-Authors: Tao Chen, Gilles Charbit, Sami HakolaAbstract:In this paper, we analyze the challenges of the interference environment in a hybrid network that consists of the device-to-device (D2D communication based ad-hoc connections and conventional Cellular connections. Accordingly, time hopping (TH) based radio resource allocation schemes aiming to improve the robustness of the hybrid network are proposed. The performance improvement even with the simple random TH scheme is considerable, which is validated via extensive simulations. In addition, the simulation results also give some hints on the optimization of the practical TH operation in a hybrid network.
Sami Hakola - One of the best experts on this subject based on the ideXlab platform.
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Clustering concept using device-to-device communication in Cellular System
IEEE Wireless Communications and Networking Conference WCNC, 2010Co-Authors: Timo Koskela, Sami Hakola, Tao Chen, Janne LehtomakiAbstract:We study how direct communication within a group of devices, cluster, can improve the performance of a conventional Cellular System. The clusters are formed from devices that are close and communicating with each other, for example, sharing data. The clusters share the radio resources among other devices in the System thus creating a mixed network System comprising directly communicating devices and devices having radio links to and from the base stations. In this kind of a System the additional challenge is to decide when clusters shall use direct communication and when conventional Cellular radio links to communicate with each other. Here, in addition to clustering concept description we provide new means to analyse achievable System performance when clustering communication is integrated into a Cellular network and especially into an interference limited System.
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Device-to-device (D2D) communication in Cellular network - Performance analysis of optimum and practical communication mode selection
IEEE Wireless Communications and Networking Conference WCNC, 2010Co-Authors: Sami Hakola, Janne Lehtoma, Tao Chen, Timo KoskelaAbstract:In a Cellular network System one way to increase its capacity is to allow direct communication between closely located user devices when they are communicating with each other instead of conveying data from one device to the other via the radio and core network. The problem is then when the network shall assign direct communication mode and when not. In previous works the decision has been done individually per communicating device pair not taking into account other devices and the current state of the network. We derive means for getting optimal communication mode for all devices in the System in terms of System equations. The System equations capture information of the network such as link gains, noise levels, signal-to-interference-and-noise-ratios, etc., as well as communication mode selection for the devices. Using the derived equations performance bounds for the Cellular System where D2D communication is an additional communication mode are illustrated via simulations. Further, practical communication mode selection algorithms are used to evaluate their System performance against the achievable bounds. Analysis show the usability of the System equations and the potential of having D2D operation integrated into a Cellular System when there is enough local communication occurring.
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Time hopping for device-to-device communication in LTE Cellular System
IEEE Wireless Communications and Networking Conference WCNC, 2010Co-Authors: Tao Chen, Gilles Charbit, Sami HakolaAbstract:In this paper, we analyze the challenges of the interference environment in a hybrid network that consists of the device-to-device (D2D communication based ad-hoc connections and conventional Cellular connections. Accordingly, time hopping (TH) based radio resource allocation schemes aiming to improve the robustness of the hybrid network are proposed. The performance improvement even with the simple random TH scheme is considerable, which is validated via extensive simulations. In addition, the simulation results also give some hints on the optimization of the practical TH operation in a hybrid network.
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The investigation of power control schemes for a device - To-device communication integrated into OFDMA Cellular System
IEEE International Symposium on Personal Indoor and Mobile Radio Communications PIMRC, 2010Co-Authors: Hongnian Xing, Sami HakolaAbstract:Power control is one of the key functions which are able to co-ordinate the System interference. In this paper, several power control schemes are investigated for a hybrid LTE System, which combines the direct device-to-device (D2D) mode communication and the normal Cellular mode communication. In the System study, the power control for the D2D mode communication is emphasized. In general, the utilization of local area transmission for D2D communications provides a better SINR than normal Cellular communications. In this case, the proper power control for D2D communications can be a flexible way to improve (and balance) the overall System performance. Naturally, the low power transmission of D2D communications leads to many potential advantages, such as low interference level (to normal Cellular users) and low power consumption. From the power control point of view, the low power transmission provides more freedom to tune the Tx power. However, power control is not an efficient solution to avoid the strong mutual (co-channel) interference between different types of UEs. In this case, the join consideration of mode selection, resource scheduling, link adaption and power control is needed.
Tao Peng - One of the best experts on this subject based on the ideXlab platform.
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Effective interference cancellation scheme for device-to-device communication underlaying Cellular networks
IEEE Vehicular Technology Conference, 2010Co-Authors: Haiming Wang, Qing Huang, Tao Chen, Tao PengAbstract:It is expected that Device-to-Device (D2D) communication is allowed to underlay future Cellular networks such as IMT-Advanced for spectrum efficiency. However, by reusing the uplink spectrums with the Cellular System, the interference to D2D users has to be addressed to maximize the overall System performance. In this paper, a novel method to deal with the resource allocation and interference avoidance issues by utilizing the network peculiarity of a hybrid network to share the uplink resource is proposed and the implementation details are described in a real Cellular System. Simulation results prove that satisfying performance can be achieved by using the proposed mechanism.
Hitoshi Yoshino - One of the best experts on this subject based on the ideXlab platform.
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theoretical capacity and outage rate of ofdma Cellular System with fractional frequency reuse
Vehicular Technology Conference, 2008Co-Authors: Hiromasa Fujii, Hitoshi YoshinoAbstract:Employing fractional frequency reuse (FFR) in OFDMA Cellular Systems is attracting a lot of attention since it offers large capacity and one-cell frequency reuse. However its performance under practical environments has not been revealed. This paper analyzes the theoretical capacity and outage rate of an OFDMA Cellular System employing FFR. Numerical examples show that FFR achieves higher capacity than the non-FFR equivalent when the outage rate is low.
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area coverage and capacity enhancement by multihop connection of cdma Cellular network
Vehicular Technology Conference, 2002Co-Authors: Atsushi Fujiwara, Hitoshi Yoshino, Shinji Takeda, T OtsuAbstract:In future broadband communication Systems, a multi-hop scheme, in which stations between a mobile terminal and a base station relay signal transmissions, seems a promising approach for wide-area coverage and System capacity enhancement. We apply the multi-hop connection scheme to a code division multiple access (CDMA) Cellular System and compare its performance to that of a conventional single-hop Cellular System. In computer simulations, we assume a packet-based multi-cell environment considering intercell and intracell interference and that every mobile station is equipped with a function for relaying transmission signals. Simulations are performed for the cases where the area coverage cannot be obtained by using only a single-hop connection, and where full area coverage is obtained by a single-hop connection. In the former case, almost 90% of area coverage is obtained when the area coverage by a single hop is approximately 50%. In the latter case, packet arrival ratio is increased by using a multi-hop connection. The degree of improvement, however, is very slight due to interference between signals from base stations and relay stations.
Timo Koskela - One of the best experts on this subject based on the ideXlab platform.
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Clustering concept using device-to-device communication in Cellular System
IEEE Wireless Communications and Networking Conference WCNC, 2010Co-Authors: Timo Koskela, Sami Hakola, Tao Chen, Janne LehtomakiAbstract:We study how direct communication within a group of devices, cluster, can improve the performance of a conventional Cellular System. The clusters are formed from devices that are close and communicating with each other, for example, sharing data. The clusters share the radio resources among other devices in the System thus creating a mixed network System comprising directly communicating devices and devices having radio links to and from the base stations. In this kind of a System the additional challenge is to decide when clusters shall use direct communication and when conventional Cellular radio links to communicate with each other. Here, in addition to clustering concept description we provide new means to analyse achievable System performance when clustering communication is integrated into a Cellular network and especially into an interference limited System.
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Device-to-device (D2D) communication in Cellular network - Performance analysis of optimum and practical communication mode selection
IEEE Wireless Communications and Networking Conference WCNC, 2010Co-Authors: Sami Hakola, Janne Lehtoma, Tao Chen, Timo KoskelaAbstract:In a Cellular network System one way to increase its capacity is to allow direct communication between closely located user devices when they are communicating with each other instead of conveying data from one device to the other via the radio and core network. The problem is then when the network shall assign direct communication mode and when not. In previous works the decision has been done individually per communicating device pair not taking into account other devices and the current state of the network. We derive means for getting optimal communication mode for all devices in the System in terms of System equations. The System equations capture information of the network such as link gains, noise levels, signal-to-interference-and-noise-ratios, etc., as well as communication mode selection for the devices. Using the derived equations performance bounds for the Cellular System where D2D communication is an additional communication mode are illustrated via simulations. Further, practical communication mode selection algorithms are used to evaluate their System performance against the achievable bounds. Analysis show the usability of the System equations and the potential of having D2D operation integrated into a Cellular System when there is enough local communication occurring.
