The Experts below are selected from a list of 6228 Experts worldwide ranked by ideXlab platform

G. De Veciana - One of the best experts on this subject based on the ideXlab platform.

  • Architecture and Abstractions for Environment and Traffic Aware System-Level Coordination of Wireless Networks: The Downlink Case
    IEEE INFOCOM 2008 - The 27th Conference on Computer Communications, 2008
    Co-Authors: B. Rengarajan, G. De Veciana
    Abstract:

    Two ways to substantially enhance wireless broadband capacity are full frequency reuse and smaller cells, both of which result in operational regimes that are highly dynamic and interference limited. This paper presents a system-level approach to interference management, that has reasonable backhaul communication and computation requirements. The basis for the approach is clustering and aggregation of measurements of the spatial diversity in sensitivity to interference associated with average user populations. This enables the system to exchange information and optimize coordinated transmission schedules using only coarse grained data. The paper explores various ways of optimizing such schedules: from a static, decoupled version to a dynamic version capturing user-level scheduling, fluctuating loads and inter-cell interference that couples base stations' performance. Based on extensive system-level simulations, we demonstrate reductions in file transfer delay ranging from 20-80%, from light to heavy loads, as compared to a simple baseline not unlike those in the field today. This improvement is achieved while providing more uniform coverage, and reducing base station power consumption by up to 45%.

  • INFOCOM - Architecture and Abstractions for Environment and Traffic Aware System-Level Coordination of Wireless Networks: The Downlink Case
    IEEE INFOCOM 2008 - The 27th Conference on Computer Communications, 2008
    Co-Authors: B. Rengarajan, G. De Veciana
    Abstract:

    Two ways to substantially enhance wireless broadband capacity are full frequency reuse and smaller cells, both of which result in operational regimes that are highly dynamic and interference limited. This paper presents a system-level approach to interference management, that has reasonable backhaul communication and computation requirements. The basis for the approach is clustering and aggregation of measurements of the spatial diversity in sensitivity to interference associated with average user populations. This enables the system to exchange information and optimize coordinated transmission schedules using only coarse grained data. The paper explores various ways of optimizing such schedules: from a static, decoupled version to a dynamic version capturing user-level scheduling, fluctuating loads and inter-cell interference that couples base stations' performance. Based on extensive system-level simulations, we demonstrate reductions in file transfer delay ranging from 20-80%, from light to heavy loads, as compared to a simple baseline not unlike those in the field today. This improvement is achieved while providing more uniform coverage, and reducing base station power consumption by up to 45%.

B. Rengarajan - One of the best experts on this subject based on the ideXlab platform.

  • Architecture and Abstractions for Environment and Traffic Aware System-Level Coordination of Wireless Networks: The Downlink Case
    IEEE INFOCOM 2008 - The 27th Conference on Computer Communications, 2008
    Co-Authors: B. Rengarajan, G. De Veciana
    Abstract:

    Two ways to substantially enhance wireless broadband capacity are full frequency reuse and smaller cells, both of which result in operational regimes that are highly dynamic and interference limited. This paper presents a system-level approach to interference management, that has reasonable backhaul communication and computation requirements. The basis for the approach is clustering and aggregation of measurements of the spatial diversity in sensitivity to interference associated with average user populations. This enables the system to exchange information and optimize coordinated transmission schedules using only coarse grained data. The paper explores various ways of optimizing such schedules: from a static, decoupled version to a dynamic version capturing user-level scheduling, fluctuating loads and inter-cell interference that couples base stations' performance. Based on extensive system-level simulations, we demonstrate reductions in file transfer delay ranging from 20-80%, from light to heavy loads, as compared to a simple baseline not unlike those in the field today. This improvement is achieved while providing more uniform coverage, and reducing base station power consumption by up to 45%.

  • INFOCOM - Architecture and Abstractions for Environment and Traffic Aware System-Level Coordination of Wireless Networks: The Downlink Case
    IEEE INFOCOM 2008 - The 27th Conference on Computer Communications, 2008
    Co-Authors: B. Rengarajan, G. De Veciana
    Abstract:

    Two ways to substantially enhance wireless broadband capacity are full frequency reuse and smaller cells, both of which result in operational regimes that are highly dynamic and interference limited. This paper presents a system-level approach to interference management, that has reasonable backhaul communication and computation requirements. The basis for the approach is clustering and aggregation of measurements of the spatial diversity in sensitivity to interference associated with average user populations. This enables the system to exchange information and optimize coordinated transmission schedules using only coarse grained data. The paper explores various ways of optimizing such schedules: from a static, decoupled version to a dynamic version capturing user-level scheduling, fluctuating loads and inter-cell interference that couples base stations' performance. Based on extensive system-level simulations, we demonstrate reductions in file transfer delay ranging from 20-80%, from light to heavy loads, as compared to a simple baseline not unlike those in the field today. This improvement is achieved while providing more uniform coverage, and reducing base station power consumption by up to 45%.

Hoyoun Kim - One of the best experts on this subject based on the ideXlab platform.

  • Achievable Degrees of Freedom of Relay-Aided MIMO Cellular Networks Using Opposite Directional Interference Alignment
    IEEE Transactions on Communications, 2019
    Co-Authors: Hoyoun Kim
    Abstract:

    In this paper, we propose an interference alignment (IA) scheme for the multiple-input multiple-output (MIMO) uplink cellular network with the help of a relay which operates in half-duplex mode. The proposed scheme only requires global channel state information (CSI) knowledge at the relay, with no transmitter beamforming and time extension at the user equipment (UE), which differs from conventional IA schemes for cellular networks. We derive the feasibility condition of the proposed scheme for the general cellular network configuration and analyze the degrees-of-freedom (DoF) performance of the proposed IA scheme while providing a closed-form beamformer design at the relay. Extensions of the proposed scheme to Downlink and full-duplex cellular networks are also proposed in this paper. The DoF performance of the proposed scheme is compared to those of linear IA scheme and relay-aided interference management scheme for a cellular network with no time extension. It is also shown that advantages similar to those in the uplink Case can be obtained for the Downlink Case through the duality of a relay-aided interfering multiple-access channel (IMAC) and an interfering broadcast channel (IBC). Furthermore, the proposed scheme for a full-duplex cellular network is shown to have advantages identical to those of a number of proposed half-duplex cellular Cases.

  • Relay-Aided MIMO Cellular Networks Using Opposite Directional Interference Alignment
    arXiv: Information Theory, 2017
    Co-Authors: Hoyoun Kim
    Abstract:

    In this paper, we first propose interference alignment (IA) scheme for uplink transmission of multiple-input-mulitple-output (MIMO) cellular network with a help of relay which operates in halfduplex mode. The proposed scheme only requires global channel state information (CSI) knowledge at relay and no transmitter beamforming and time extension is required at user equipment (UE), which differs from the conventional IA schemes for cellular network. We derive the feasibility condition of the proposed scheme for the general network configuration and analyze the degrees-of-freedom (DoF) performance of the proposed IA scheme. Extension of proposed scheme for Downlink and full-duplex network are further described in this paper. It is also shown that the same advantage as the uplink Case can be obtained for Downlink Case through relay induced interfering multiple access channel (IMAC) and interfering broadcast channel (IBC) duality. Furthermore, full-duplex network is shown to have same advantages with half-duplex Cases.

Werner Wiesbeck - One of the best experts on this subject based on the ideXlab platform.

  • A modelling approach for multiuser MIMO systems including spatially-colored interference
    GLOBECOM - IEEE Global Telecommunications Conference, 2004
    Co-Authors: T. Fugen, C. Kuhnert, J. Maurer, Werner Wiesbeck
    Abstract:

    This paper deals with the investigation of MIMO (multiple input multiple output) systems on system level including interference. The interference affects the capacity of each user and depends on the spatial characteristics of the propagation channel. It is spatially-colored. A necessary step towards a realistic performance evaluation is to include interference into channel modelling process. A new multiuser double-directional channel model (MDDCM) that enables a correct interference description is presented in this paper. It is based on a distributed scatterer approach and includes line-of-sight areas, far clusters and new models for street guided and over rooftop propagation. Simulation results of a cellular multiuser MIMO system for the Downlink Case based on the MDDCM are presented. With this tool it becomes possible to evaluate the performance of multiuser MIMO systems under realistic propagation and interference conditions. © 2004 IEEE.

  • WSA - Performance of multiuser MIMO systems under realistic propagation conditions
    ITG Workshop on Smart Antennas (IEEE Cat. No.04EX802), 1
    Co-Authors: T. Fugen, C. Kuhnert, J. Maurer, Werner Wiesbeck
    Abstract:

    Many studies investigate wireless communication systems with multiple antennas on both sides of the link (MIMO systems) for future high-speed mobile communications. With these systems, the spatial properties of the propagation channel can be exploited. This paper deals with the investigation of MIMO systems on system level for the Downlink Case. In this scenario multiuser interference affects the capacity of each user. The interference depends on the spatial characteristics of the propagation channel. It is spatially-colored. A necessary step towards realistic simulation results is to include the spatial dependencies between different users via directional information on the angle of arrival of the multiuser interference. A new multiuser double-directional channel model (MDDCM), which fulfils this constraint, is presented in this paper, ft is based on a geometry approach with fixed scatterers and includes line-of-sight areas, far clusters and new models for street guided and over rooftop propagation. Simulation results of a cellular multiuser MIMO system for the Downlink Case based on the MDDCM are presented. With this tool it becomes possible to evaluate the performance of multiuser MIMO systems under realistic propagation and interference conditions

  • GLOBECOM - A modelling approach for multiuser MIMO systems including spatially-colored interference [cellular example]
    IEEE Global Telecommunications Conference 2004. GLOBECOM '04., 1
    Co-Authors: T. Fugen, C. Kuhnert, J. Maurer, Werner Wiesbeck
    Abstract:

    This paper deals with the investigation of MIMO (multiple input multiple output) systems on a system level, including interference. The interference affects the capacity of each user and depends on the spatial characteristics of the propagation channel. It is spatially-colored. A necessary step towards a realistic performance evaluation is to include interference into the channel modelling process. A new multiuser double-directional channel model (MDDCM), that enables a correct interference description, is presented in this paper. It is based on a distributed scatterer approach and includes line-of-sight areas, far clusters and new models for street guided and over-rooftop propagation. Simulation results of a cellular multiuser MIMO system for the Downlink Case, based on the MDDCM, are presented. With this tool, it becomes possible to evaluate the performance of multiuser MIMO systems under realistic propagation and interference conditions.

  • PIMRC - Capacity of the MIMO broadcast channel under realistic propagation conditions
    2005 IEEE 16th International Symposium on Personal Indoor and Mobile Radio Communications, 1
    Co-Authors: T. Fugen, C. Kuhnert, Werner Wiesbeck
    Abstract:

    In this paper simulation results of the multiuser MIMO broadcast channel are presented. The MIMO broadcast channel corresponds to the Downlink Case where the base station sends simultaneously different information to several users in the cell. In contrast to many information theoretical studies, the presented results are based on a realistic MIMO channel model and are therefore a first step towards realistic performance evaluations. The channel model is called multiuser double-directional channel model (MDDCM) and was introduced recently in T. Fugen et al., (2004). It is based on a geometry approach with fixed scatterers. It enables a realistic description of the desired link as well as the spatially-colored interference in a macro-cellular environment. Based on the MDDCM the sum capacity of the MIMO broadcast channel for a varying number of users and varying antenna configurations in an isolated communication cell is presented. To achieve the sum capacity the duality to the MIMO multiple access channels is used

Mérouane Debbah - One of the best experts on this subject based on the ideXlab platform.

  • Spatial games combining base station placement and mobile association: the Downlink Case
    2010
    Co-Authors: Alonso Silva, Hamidou Tembine, Eitan Altman, Mérouane Debbah
    Abstract:

    We study the mobile association problem: we determine the cells corresponding to each base station, i.e, the locations at which intelligent mobile terminals prefer to connect to a given base station rather than to others. This paper proposes a new approach based on optimal transport theory to characterize the solution based on previous works on fluid approximations. We are able to characterize the global optimal solution, as well as the user optimal solution, for the Downlink Case problem.

  • Spatial games and global optimization for the mobile association problem: the Downlink Case
    2010
    Co-Authors: Alonso Silva, Hamidou Tembine, Eitan Altman, Mérouane Debbah
    Abstract:

    We study the mobile association problem: we determine the cells corresponding to each base station, i.e, the locations at which intelligent mobile terminals prefer to connect to a given base station rather than to others. This paper proposes a new approach based on optimal transport theory to characterize the solution based on previous works on fluid approximations. We are able to characterize the global optimal solution, as well as the user optimal solution, for the Downlink Case problem.

  • spatial games and global optimization for the mobile association problem the Downlink Case
    Conference on Decision and Control, 2010
    Co-Authors: Alonso Silva, Hamidou Tembine, Eitan Altman, Mérouane Debbah
    Abstract:

    We study the mobile association problem: we determine the cells corresponding to each base station, i.e, the locations at which intelligent mobile terminals prefer to connect to a given base station rather than to others. This paper proposes a new approach based on optimal transport theory to characterize the solution based on previous works on fluid approximations. We characterize the optimal solution from both the global network and the individual user points of view, for the Downlink setting.

  • Spatial Games for the Downlink Case combining base station placement and mobile association
    2010
    Co-Authors: Alonso Silvaz, Eitan Altman, Mérouane Debbah, Tembine Hamidou
    Abstract:

    AbstractWe study the mobile association problem: we determine the ce lls correspondingto each basestation, i.e, the locations at which intelligent mobile ter minals prefer to connect to a given basestation rather than to others. This paper proposes a new appr oach based on optimal transporttheory to characterize the solution based on previous works on uid approximations. We areable to characterize the global optimal solution, as well as the user optimal solution, for theDownlink Case problem. 1 INTRODUCTION We consider the Case where intelligent mobile terminals, capable of acc essing multiple radio accesstechnologies, will decide for themselves the wireless access techno logy to use and the access pointto which to connect. Within this context, we study the mobile associa tion problem, where wedetermine the locations at which intelligent mobile terminals prefer to c onnect to a given basestation rather than to others.Forthe user optimization problem, considering the interactions with other mobile terminals, startingfrom the seminal paper ofHotelling [1] alarge area of research on loc ation games has been developed.His paper [1] introduced the notion of spatial competition in a duopoly situation. Plastria [2]presented an overview of the research on locating one or more new facilities in an environment wherecompeting facilities already exist. Gabszewicz and Thisse [3] provided another general overviewon location games. Altman et al. [4] studied the duopoly situation in the uplink Case in a linesegment and realized that with the particular cost structure that arises in the cellular context morecomplex cells are obtained at equilibrium. Our work focuses on the dow nlink Case and in a moregeneral situation where a nite number of base stations can compe te in a one-dimensional andtwo-dimensional Case without any assumption on the symmetry of t he users location. In orderto do that, we propose a new framework for mobile association prob lems using optimal transport

  • CDC - Spatial games and global optimization for the mobile association problem: The Downlink Case
    49th IEEE Conference on Decision and Control (CDC), 2010
    Co-Authors: Alonso Silva, Hamidou Tembine, Eitan Altman, Mérouane Debbah
    Abstract:

    We study the mobile association problem: we determine the cells corresponding to each base station, i.e, the locations at which intelligent mobile terminals prefer to connect to a given base station rather than to others. This paper proposes a new approach based on optimal transport theory to characterize the solution based on previous works on fluid approximations. We characterize the optimal solution from both the global network and the individual user points of view, for the Downlink setting.