The Experts below are selected from a list of 180 Experts worldwide ranked by ideXlab platform

Maged Elkashlan - One of the best experts on this subject based on the ideXlab platform.

  • Physical Layer Security in Uplink NOMA Multi-Antenna Systems With Randomly Distributed Eavesdroppers
    IEEE Access, 2019
    Co-Authors: Gerardo Gómez, Francisco J. Martin-vega, F. Javier Lopez-martinez, Maged Elkashlan
    Abstract:

    The physical layer security of uplink non-orthogonal multiple access (NOMA) is analyzed. A stochastic geometry approach is applied to analyze the coverage probability and effective secrecy throughput (EST) of the kth NOMA user, where a fixed or an adaptive transmission rate can be used. We consider a protected zone around the legitimate terminals to establish an eavesdropper-Exclusion Area. We assume that the channel state information associated with eavesdroppers is not available at the base station. We also consider that the base station is equipped with multiple antennas. The impact of imperfect successive interference cancellation is also taken into account in this paper. Our framework allows to compute, numerically, the wiretap code rates that maximize the EST. In addition, our framework also allows an optimum selection of other system parameters, such as the transmit power or the eavesdropper-Exclusion radius.

  • Physical Layer Security in Uplink NOMA Multi-Antenna Systems with Randomly Distributed Eavesdroppers
    arXiv: Information Theory, 2017
    Co-Authors: Gerardo Gómez, Francisco J. Martin-vega, F. Javier Lopez-martinez, Maged Elkashlan
    Abstract:

    The physical layer security of uplink non-orthogonal multiple access (NOMA) is analyzed. A stochastic geometry approach is applied to analyze the coverage probability and the effective secrecy throughput (EST) of the kth NOMA user, where a fixed or an adaptive transmission rate can be used. A protected zone around the legitimate terminals to establish an eavesdropper-Exclusion Area. We assume that the channel state information associated with eavesdroppers is not available at the base station. We consider that the base station is equipped with multiple antennas. The impact of imperfect successive interference cancellation is also taken into account in this work. Our analysis allows an easy selection of the wiretap code rates that maximizes the EST. Additionally, our framework also allows an optimum selection of other system parameters like the transmit power or the eavesdropper-Exclusion radius.

  • Uplink NOMA in Large-Scale Systems: Coverage and Physical Layer Security.
    2017
    Co-Authors: Gerardo Gómez, Francisco J. Martin-vega, F. Javier Lopez-martinez, Maged Elkashlan
    Abstract:

    In this paper, the physical layer security of uplink non-orthogonal multiple access (NOMA) in large-scale networks is analyzed. An stochastic geometry approach is applied to derive new analytical expressions for the coverage probability and the effective secrecy throughput (EST) of the kth NOMA user, which may use a fixed or an adaptive transmission rate. We consider a protected zone around the legitimate terminals to establish an eavesdropper-Exclusion Area. We assume that the channel state information associated with eavesdroppers is not available at the base station. The impact of an imperfect successive interference cancellation is also taken into account in this work. Our analysis allows an easy selection of the wiretap code rates that maximizes the EST. In addition, our framework also allows an optimum selection of other system parameters like the transmit power or the eavesdropper-Exclusion radius.

  • Enhancing the Physical Layer Security of Non-Orthogonal Multiple Access in Large-Scale Networks
    IEEE Transactions on Wireless Communications, 2017
    Co-Authors: Yuanwei Liu, Maged Elkashlan, Zhijin Qin, Yue Gao, Lajos Hanzo
    Abstract:

    This paper investigates the physical layer security of non-orthogonal multiple access (NOMA) in large-scale networks with invoking stochastic geometry. Both single-antenna and multiple-antenna aided transmission scenarios are considered, where the base station (BS) communicates with randomly distributed NOMA users. In the single-antenna scenario, we adopt a protected zone around the BS to establish an eavesdropper-Exclusion Area with the aid of careful channel ordering of the NOMA users. In the multiple-antenna scenario, artificial noise is generated at the BS for further improving the security of a beamforming-aided system. In order to characterize the secrecy performance, we derive new exact expressions of the security outage probability for both single-antenna and multiple-antenna aided scenarios. For the single-antenna scenario, we perform secrecy diversity order analysis of the selected user pair. The analytical results derived demonstrate that the secrecy diversity order is determined by the specific user having the worse channel condition among the selected user pair. For the multiple-antenna scenario, we derive the asymptotic secrecy outage probability, when the number of transmit antennas tends to infinity. Monte Carlo simulations are provided for verifying the analytical results derived and to show that: 1) the security performance of the NOMA networks can be improved by invoking the protected zone and by generating artificial noise at the BS and 2) the asymptotic secrecy outage probability is close to the exact secrecy outage probability.

Lajos Hanzo - One of the best experts on this subject based on the ideXlab platform.

  • Enhancing the Physical Layer Security of Non-Orthogonal Multiple Access in Large-Scale Networks
    IEEE Transactions on Wireless Communications, 2017
    Co-Authors: Yuanwei Liu, Maged Elkashlan, Zhijin Qin, Yue Gao, Lajos Hanzo
    Abstract:

    This paper investigates the physical layer security of non-orthogonal multiple access (NOMA) in large-scale networks with invoking stochastic geometry. Both single-antenna and multiple-antenna aided transmission scenarios are considered, where the base station (BS) communicates with randomly distributed NOMA users. In the single-antenna scenario, we adopt a protected zone around the BS to establish an eavesdropper-Exclusion Area with the aid of careful channel ordering of the NOMA users. In the multiple-antenna scenario, artificial noise is generated at the BS for further improving the security of a beamforming-aided system. In order to characterize the secrecy performance, we derive new exact expressions of the security outage probability for both single-antenna and multiple-antenna aided scenarios. For the single-antenna scenario, we perform secrecy diversity order analysis of the selected user pair. The analytical results derived demonstrate that the secrecy diversity order is determined by the specific user having the worse channel condition among the selected user pair. For the multiple-antenna scenario, we derive the asymptotic secrecy outage probability, when the number of transmit antennas tends to infinity. Monte Carlo simulations are provided for verifying the analytical results derived and to show that: 1) the security performance of the NOMA networks can be improved by invoking the protected zone and by generating artificial noise at the BS and 2) the asymptotic secrecy outage probability is close to the exact secrecy outage probability.

Joan Subirats - One of the best experts on this subject based on the ideXlab platform.

  • social Exclusion Area effects and metropolitan governance a comparative analysis of five large spanish cities
    Urban Research & Practice, 2008
    Co-Authors: Ismael Blanco, Joan Subirats
    Abstract:

    As a first step towards the exploration of the particularities urban social Exclusion in Spain, the research presented here evaluates the significance of the urban territorial factor at neighbourhood level in order to develop relevant conclusions for the design of urban policies. After comparing the structure and dynamics of socio-spatial inequalities in five large Spanish cities (Madrid, Barcelona, Bilbao, Seville and Murcia), we analyse how different disadvantaged neighbourhoods – inner city districts and peripheral housing estates – affect the life trajectories of different vulnerable social groups: long-term unemployed males, undocumented immigrants, single mothers, old people living alone and young people with a low education level and job problems. We identify the existence of significant differences between inner city districts and peripheral housing estates regarding the way they affect the life chances of their inhabitants. Furthermore, we show how different social groups are unequally affected b...

Gerardo Gómez - One of the best experts on this subject based on the ideXlab platform.

  • Physical Layer Security in Uplink NOMA Multi-Antenna Systems With Randomly Distributed Eavesdroppers
    IEEE Access, 2019
    Co-Authors: Gerardo Gómez, Francisco J. Martin-vega, F. Javier Lopez-martinez, Maged Elkashlan
    Abstract:

    The physical layer security of uplink non-orthogonal multiple access (NOMA) is analyzed. A stochastic geometry approach is applied to analyze the coverage probability and effective secrecy throughput (EST) of the kth NOMA user, where a fixed or an adaptive transmission rate can be used. We consider a protected zone around the legitimate terminals to establish an eavesdropper-Exclusion Area. We assume that the channel state information associated with eavesdroppers is not available at the base station. We also consider that the base station is equipped with multiple antennas. The impact of imperfect successive interference cancellation is also taken into account in this paper. Our framework allows to compute, numerically, the wiretap code rates that maximize the EST. In addition, our framework also allows an optimum selection of other system parameters, such as the transmit power or the eavesdropper-Exclusion radius.

  • Physical Layer Security in Uplink NOMA Multi-Antenna Systems with Randomly Distributed Eavesdroppers
    arXiv: Information Theory, 2017
    Co-Authors: Gerardo Gómez, Francisco J. Martin-vega, F. Javier Lopez-martinez, Maged Elkashlan
    Abstract:

    The physical layer security of uplink non-orthogonal multiple access (NOMA) is analyzed. A stochastic geometry approach is applied to analyze the coverage probability and the effective secrecy throughput (EST) of the kth NOMA user, where a fixed or an adaptive transmission rate can be used. A protected zone around the legitimate terminals to establish an eavesdropper-Exclusion Area. We assume that the channel state information associated with eavesdroppers is not available at the base station. We consider that the base station is equipped with multiple antennas. The impact of imperfect successive interference cancellation is also taken into account in this work. Our analysis allows an easy selection of the wiretap code rates that maximizes the EST. Additionally, our framework also allows an optimum selection of other system parameters like the transmit power or the eavesdropper-Exclusion radius.

  • Uplink NOMA in Large-Scale Systems: Coverage and Physical Layer Security.
    2017
    Co-Authors: Gerardo Gómez, Francisco J. Martin-vega, F. Javier Lopez-martinez, Maged Elkashlan
    Abstract:

    In this paper, the physical layer security of uplink non-orthogonal multiple access (NOMA) in large-scale networks is analyzed. An stochastic geometry approach is applied to derive new analytical expressions for the coverage probability and the effective secrecy throughput (EST) of the kth NOMA user, which may use a fixed or an adaptive transmission rate. We consider a protected zone around the legitimate terminals to establish an eavesdropper-Exclusion Area. We assume that the channel state information associated with eavesdroppers is not available at the base station. The impact of an imperfect successive interference cancellation is also taken into account in this work. Our analysis allows an easy selection of the wiretap code rates that maximizes the EST. In addition, our framework also allows an optimum selection of other system parameters like the transmit power or the eavesdropper-Exclusion radius.

Yuanwei Liu - One of the best experts on this subject based on the ideXlab platform.

  • Enhancing the Physical Layer Security of Non-Orthogonal Multiple Access in Large-Scale Networks
    IEEE Transactions on Wireless Communications, 2017
    Co-Authors: Yuanwei Liu, Maged Elkashlan, Zhijin Qin, Yue Gao, Lajos Hanzo
    Abstract:

    This paper investigates the physical layer security of non-orthogonal multiple access (NOMA) in large-scale networks with invoking stochastic geometry. Both single-antenna and multiple-antenna aided transmission scenarios are considered, where the base station (BS) communicates with randomly distributed NOMA users. In the single-antenna scenario, we adopt a protected zone around the BS to establish an eavesdropper-Exclusion Area with the aid of careful channel ordering of the NOMA users. In the multiple-antenna scenario, artificial noise is generated at the BS for further improving the security of a beamforming-aided system. In order to characterize the secrecy performance, we derive new exact expressions of the security outage probability for both single-antenna and multiple-antenna aided scenarios. For the single-antenna scenario, we perform secrecy diversity order analysis of the selected user pair. The analytical results derived demonstrate that the secrecy diversity order is determined by the specific user having the worse channel condition among the selected user pair. For the multiple-antenna scenario, we derive the asymptotic secrecy outage probability, when the number of transmit antennas tends to infinity. Monte Carlo simulations are provided for verifying the analytical results derived and to show that: 1) the security performance of the NOMA networks can be improved by invoking the protected zone and by generating artificial noise at the BS and 2) the asymptotic secrecy outage probability is close to the exact secrecy outage probability.