23,171 research outputs found
Coexistence of RF-powered IoT and a Primary Wireless Network with Secrecy Guard Zones
This paper studies the secrecy performance of a wireless network (primary
network) overlaid with an ambient RF energy harvesting IoT network (secondary
network). The nodes in the secondary network are assumed to be solely powered
by ambient RF energy harvested from the transmissions of the primary network.
We assume that the secondary nodes can eavesdrop on the primary transmissions
due to which the primary network uses secrecy guard zones. The primary
transmitter goes silent if any secondary receiver is detected within its guard
zone. Using tools from stochastic geometry, we derive the probability of
successful connection of the primary network as well as the probability of
secure communication. Two conditions must be jointly satisfied in order to
ensure successful connection: (i) the SINR at the primary receiver is above a
predefined threshold, and (ii) the primary transmitter is not silent. In order
to ensure secure communication, the SINR value at each of the secondary nodes
should be less than a predefined threshold. Clearly, when more secondary nodes
are deployed, more primary transmitters will remain silent for a given guard
zone radius, thus impacting the amount of energy harvested by the secondary
network. Our results concretely show the existence of an optimal deployment
density for the secondary network that maximizes the density of nodes that are
able to harvest sufficient amount of energy. Furthermore, we show the
dependence of this optimal deployment density on the guard zone radius of the
primary network. In addition, we show that the optimal guard zone radius
selected by the primary network is a function of the deployment density of the
secondary network. This interesting coupling between the two networks is
studied using tools from game theory. Overall, this work is one of the few
concrete works that symbiotically merge tools from stochastic geometry and game
theory
Principles of Physical Layer Security in Multiuser Wireless Networks: A Survey
This paper provides a comprehensive review of the domain of physical layer
security in multiuser wireless networks. The essential premise of
physical-layer security is to enable the exchange of confidential messages over
a wireless medium in the presence of unauthorized eavesdroppers without relying
on higher-layer encryption. This can be achieved primarily in two ways: without
the need for a secret key by intelligently designing transmit coding
strategies, or by exploiting the wireless communication medium to develop
secret keys over public channels. The survey begins with an overview of the
foundations dating back to the pioneering work of Shannon and Wyner on
information-theoretic security. We then describe the evolution of secure
transmission strategies from point-to-point channels to multiple-antenna
systems, followed by generalizations to multiuser broadcast, multiple-access,
interference, and relay networks. Secret-key generation and establishment
protocols based on physical layer mechanisms are subsequently covered.
Approaches for secrecy based on channel coding design are then examined, along
with a description of inter-disciplinary approaches based on game theory and
stochastic geometry. The associated problem of physical-layer message
authentication is also introduced briefly. The survey concludes with
observations on potential research directions in this area.Comment: 23 pages, 10 figures, 303 refs. arXiv admin note: text overlap with
arXiv:1303.1609 by other authors. IEEE Communications Surveys and Tutorials,
201
Joint Secure Beamforming for Cognitive Radio Networks with Untrusted Secondary Users
In this paper, we consider simultaneous wireless information and power
transfer (SWIPT) in orthogonal frequency division multiple access (OFDMA)
systems with the coexistence of information receivers (IRs) and energy
receivers (ERs). The IRs are served with best-effort secrecy data and the ERs
harvest energy with minimum required harvested power. To enhance physical-layer
security and yet satisfy energy harvesting requirements, we introduce a new
frequency-domain artificial noise based approach. We study the optimal resource
allocation for the weighted sum secrecy rate maximization via transmit power
and subcarrier allocation. The considered problem is non-convex, while we
propose an efficient algorithm for solving it based on Lagrange duality method.
Simulation results illustrate the effectiveness of the proposed algorithm as
compared against other heuristic schemes.Comment: To appear in Globecom 201
Power Efficient and Secure Multiuser Communication Systems with Wireless Information and Power Transfer
In this paper, we study resource allocation algorithm design for power
efficient secure communication with simultaneous wireless information and power
transfer (WIPT) in multiuser communication systems. In particular, we focus on
power splitting receivers which are able to harvest energy and decode
information from the received signals. The considered problem is modeled as an
optimization problem which takes into account a minimum required
signal-to-interference-plus-noise ratio (SINR) at multiple desired receivers, a
maximum tolerable data rate at multiple multi-antenna potential eavesdroppers,
and a minimum required power delivered to the receivers. The proposed problem
formulation facilitates the dual use of artificial noise in providing efficient
energy transfer and guaranteeing secure communication. We aim at minimizing the
total transmit power by jointly optimizing transmit beamforming vectors, power
splitting ratios at the desired receivers, and the covariance of the artificial
noise. The resulting non-convex optimization problem is transformed into a
semidefinite programming (SDP) and solved by SDP relaxation. We show that the
adopted SDP relaxation is tight and achieves the global optimum of the original
problem. Simulation results illustrate the significant power saving obtained by
the proposed optimal algorithm compared to suboptimal baseline schemes.Comment: Accepted for presentation at the IEEE International Conference on
Communications (ICC), Sydney, Australia, 201
Max-min Fair Wireless Energy Transfer for Secure Multiuser Communication Systems
This paper considers max-min fairness for wireless energy transfer in a
downlink multiuser communication system. Our resource allocation design
maximizes the minimum harvested energy among multiple multiple-antenna energy
harvesting receivers (potential eavesdroppers) while providing quality of
service (QoS) for secure communication to multiple single-antenna information
receivers. In particular, the algorithm design is formulated as a non-convex
optimization problem which takes into account a minimum required
signal-to-interference-plus-noise ratio (SINR) constraint at the information
receivers and a constraint on the maximum tolerable channel capacity achieved
by the energy harvesting receivers for a given transmit power budget. The
proposed problem formulation exploits the dual use of artificial noise
generation for facilitating efficient wireless energy transfer and secure
communication. A semidefinite programming (SDP) relaxation approach is
exploited to obtain a global optimal solution of the considered problem.
Simulation results demonstrate the significant performance gain in harvested
energy that is achieved by the proposed optimal scheme compared to two simple
baseline schemes.Comment: 5 pages, invited paper, IEEE Information Theory Workshop 2014,
Hobart, Tasmania, Australia, Nov. 201
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