Yonsei University

Displaying 1-13 of 13 results

  • White Papers // Sep 2011

    Some Useful Distributions and Probabilities for Cellular Networks

    The cellular network is one of the most useful networks for wireless communications and now universally used. There have been a lot of analytic results about the performance of the mobile user at a specific location such as the cell center or edge. On the other hand, there have been...

    Provided By Yonsei University

  • White Papers // May 2011

    Activity Recognition Using Hierarchical Hidden Markov Models on a Smartphone With 3D Accelerometer

    As smartphone users have been increased, studies using mobile sensors on smartphone have been investigated in recent years. Activity recognition is one of the active research topics, which can be used for providing users the adaptive services with mobile devices. In this paper, an activity recognition system on a smartphone...

    Provided By Yonsei University

  • White Papers // Mar 2011

    A Stochastic-Geometry Approach to Coverage in Cellular Networks With Multi-Cell Cooperation

    Multi-cell cooperation is a promising approach for mitigating inter-cell interference in dense cellular networks. Quantifying the performance of multi-cell cooperation is challenging as it integrates physical-layer techniques and network topologies. For tractability, existing work typically relies on the over-simplified Wyner-type models. In this paper, the authors propose a new stochastic-geometry...

    Provided By Yonsei University

  • White Papers // Oct 2010

    Cooperative Feedback for Multi-Antenna Cognitive Radio Networks

    Cognitive Beamforming (CB) is a multi-antenna technique for efficient spectrum sharing between Primary Users (PUs) and Secondary Users (SUs) in a cognitive radio network. Specifically, a multi-antenna SU transmitter applies CB to suppress the interference to the PU receivers as well as enhance the corresponding SU-link performance. In this paper,...

    Provided By Yonsei University

  • White Papers // Sep 2010

    Spatial Interference Cancellation for Multi-Antenna Mobile Ad Hoc Networks

    Interference between nodes is a critical impairment in Mobile Ad hoc NETworks (MANETs). This paper studies the role of multiple antennas in mitigating such interference. Specifically, a network is studied in which receivers apply zero-forcing beamforming to cancel the strongest interferers. Assuming a network with Poisson distributed transmitters and independent...

    Provided By Yonsei University

  • White Papers // Sep 2010

    Self-Optimized Coverage Coordination in Femtocell Networks

    This paper proposes a self-optimized coverage coordination scheme for two-tier femtocell networks, in which a femtocell base station adjusts the transmit power based on the statistics of the signal and the interference power that is measured at a femtocell downlink. Furthermore, an analytic expression is derived for the coverage leakage...

    Provided By Yonsei University

  • White Papers // Feb 2010

    Achievable Transmission Capacity of Secondary System in Cognitive Radio Networks

    This paper evaluates the achievable transmission capacity of the secondary system in cognitive radio networks, defined by the spatial density of successful transmissions while guaranteeing the target outage probabilities of the secondary and the primary systems. By using stochastic geometry, the effects of the spatial densities and the transmission powers...

    Provided By Yonsei University

  • White Papers // Jan 2010

    Effective Location Acquisition Control Algorithms for the Location-Based Alert Services in Mobile Environment

    The location-based alert services can be regarded as the one of the most practical location-based services. For the services, an alert service system for the services alerts mobile device users when they enter into or leave from predefined specific regions, and provides certain services previously asked by the users for...

    Provided By Yonsei University

  • White Papers // Nov 2009

    Effective Replicated Server Allocation Algorithms in Mobile Computing Systems

    In mobile environments, mobile device users access and transfer a great deal of data through the online servers. In order to enhance users' access speed in a wireless network, decentralizing replicated servers appropriately in the network is required. Previous work regarding this issue had focused on the placement of replicated...

    Provided By Yonsei University

  • White Papers // Oct 2009

    Interference Mitigation Using Uplink Power Control for Two-Tier Femtocell Networks

    This paper proposes two interference mitigation strategies that adjust the maximum transmit power of femtocell users to suppress the cross-tier interference at a macrocell Base Station (BS). The open-loop and the closed-loop control suppress the cross-tier interference less than a fixed threshold and an adaptive threshold based on the Noise...

    Provided By Yonsei University

  • White Papers // Jun 2009

    The Traffic Prediction Multi-Path Energy-Aware Source Routing (TP-MESR) in Ad Hoc Networks

    The purpose of this paper is to suggest energy efficient routing for ad hoc networks which are composed of nodes with limited energy. There are diverse problems including limitation of energy supply of node, and the node energy management problem has been presented. And a number of protocols have been...

    Provided By Yonsei University

  • White Papers // Jun 2009

    A Mobile Multihop Relay Dynamic TDD Scheme for Cellular Networks

    In this paper, the authors present an analytical framework for the evaluation of the uplink performance of multihop cellular networks based on dynamic Time Division Duplex (TDD). New wireless broadband protocols, such as WiMAX, WiBro, and 3G-LTE apply TDD, and mobile communication protocols under standardization (e.g., IEEE802.16j) are investigating Mobile...

    Provided By Yonsei University

  • White Papers // Apr 2009

    Performance Analysis According to the Change of Cluster Size in Large Scale Wireless Sensor Networks

    In large scale sensor networks, scalability and robustness are very important, and sensor nodes are also highly power constrained. Clustering, a method of grouping sensor nodes, can meet these requirements. Sensor networks also need to support fast delivery of important and urgent data. The purpose of this paper is to...

    Provided By Yonsei University

  • White Papers // Apr 2009

    Performance Analysis According to the Change of Cluster Size in Large Scale Wireless Sensor Networks

    In large scale sensor networks, scalability and robustness are very important, and sensor nodes are also highly power constrained. Clustering, a method of grouping sensor nodes, can meet these requirements. Sensor networks also need to support fast delivery of important and urgent data. The purpose of this paper is to...

    Provided By Yonsei University

  • White Papers // Jun 2009

    A Mobile Multihop Relay Dynamic TDD Scheme for Cellular Networks

    In this paper, the authors present an analytical framework for the evaluation of the uplink performance of multihop cellular networks based on dynamic Time Division Duplex (TDD). New wireless broadband protocols, such as WiMAX, WiBro, and 3G-LTE apply TDD, and mobile communication protocols under standardization (e.g., IEEE802.16j) are investigating Mobile...

    Provided By Yonsei University

  • White Papers // Mar 2011

    A Stochastic-Geometry Approach to Coverage in Cellular Networks With Multi-Cell Cooperation

    Multi-cell cooperation is a promising approach for mitigating inter-cell interference in dense cellular networks. Quantifying the performance of multi-cell cooperation is challenging as it integrates physical-layer techniques and network topologies. For tractability, existing work typically relies on the over-simplified Wyner-type models. In this paper, the authors propose a new stochastic-geometry...

    Provided By Yonsei University

  • White Papers // Jan 2010

    Effective Location Acquisition Control Algorithms for the Location-Based Alert Services in Mobile Environment

    The location-based alert services can be regarded as the one of the most practical location-based services. For the services, an alert service system for the services alerts mobile device users when they enter into or leave from predefined specific regions, and provides certain services previously asked by the users for...

    Provided By Yonsei University

  • White Papers // Nov 2009

    Effective Replicated Server Allocation Algorithms in Mobile Computing Systems

    In mobile environments, mobile device users access and transfer a great deal of data through the online servers. In order to enhance users' access speed in a wireless network, decentralizing replicated servers appropriately in the network is required. Previous work regarding this issue had focused on the placement of replicated...

    Provided By Yonsei University

  • White Papers // Sep 2010

    Self-Optimized Coverage Coordination in Femtocell Networks

    This paper proposes a self-optimized coverage coordination scheme for two-tier femtocell networks, in which a femtocell base station adjusts the transmit power based on the statistics of the signal and the interference power that is measured at a femtocell downlink. Furthermore, an analytic expression is derived for the coverage leakage...

    Provided By Yonsei University

  • White Papers // Oct 2009

    Interference Mitigation Using Uplink Power Control for Two-Tier Femtocell Networks

    This paper proposes two interference mitigation strategies that adjust the maximum transmit power of femtocell users to suppress the cross-tier interference at a macrocell Base Station (BS). The open-loop and the closed-loop control suppress the cross-tier interference less than a fixed threshold and an adaptive threshold based on the Noise...

    Provided By Yonsei University

  • White Papers // Oct 2010

    Cooperative Feedback for Multi-Antenna Cognitive Radio Networks

    Cognitive Beamforming (CB) is a multi-antenna technique for efficient spectrum sharing between Primary Users (PUs) and Secondary Users (SUs) in a cognitive radio network. Specifically, a multi-antenna SU transmitter applies CB to suppress the interference to the PU receivers as well as enhance the corresponding SU-link performance. In this paper,...

    Provided By Yonsei University

  • White Papers // Jun 2009

    The Traffic Prediction Multi-Path Energy-Aware Source Routing (TP-MESR) in Ad Hoc Networks

    The purpose of this paper is to suggest energy efficient routing for ad hoc networks which are composed of nodes with limited energy. There are diverse problems including limitation of energy supply of node, and the node energy management problem has been presented. And a number of protocols have been...

    Provided By Yonsei University

  • White Papers // Sep 2010

    Spatial Interference Cancellation for Multi-Antenna Mobile Ad Hoc Networks

    Interference between nodes is a critical impairment in Mobile Ad hoc NETworks (MANETs). This paper studies the role of multiple antennas in mitigating such interference. Specifically, a network is studied in which receivers apply zero-forcing beamforming to cancel the strongest interferers. Assuming a network with Poisson distributed transmitters and independent...

    Provided By Yonsei University

  • White Papers // Feb 2010

    Achievable Transmission Capacity of Secondary System in Cognitive Radio Networks

    This paper evaluates the achievable transmission capacity of the secondary system in cognitive radio networks, defined by the spatial density of successful transmissions while guaranteeing the target outage probabilities of the secondary and the primary systems. By using stochastic geometry, the effects of the spatial densities and the transmission powers...

    Provided By Yonsei University

  • White Papers // Sep 2011

    Some Useful Distributions and Probabilities for Cellular Networks

    The cellular network is one of the most useful networks for wireless communications and now universally used. There have been a lot of analytic results about the performance of the mobile user at a specific location such as the cell center or edge. On the other hand, there have been...

    Provided By Yonsei University

  • White Papers // May 2011

    Activity Recognition Using Hierarchical Hidden Markov Models on a Smartphone With 3D Accelerometer

    As smartphone users have been increased, studies using mobile sensors on smartphone have been investigated in recent years. Activity recognition is one of the active research topics, which can be used for providing users the adaptive services with mobile devices. In this paper, an activity recognition system on a smartphone...

    Provided By Yonsei University