1,690 research outputs found
Security in Cognitive Radio Networks
In this paper, we investigate the information-theoretic security by modeling
a cognitive radio wiretap channel under quality-of-service (QoS) constraints
and interference power limitations inflicted on primary users (PUs). We
initially define four different transmission scenarios regarding channel
sensing results and their correctness. We provide effective secure transmission
rates at which a secondary eavesdropper is refrained from listening to a
secondary transmitter (ST). Then, we construct a channel state transition
diagram that characterizes this channel model. We obtain the effective secure
capacity which describes the maximum constant buffer arrival rate under given
QoS constraints. We find out the optimal transmission power policies that
maximize the effective secure capacity, and then, we propose an algorithm that,
in general, converges quickly to these optimal policy values. Finally, we show
the performance levels and gains obtained under different channel conditions
and scenarios. And, we emphasize, in particular, the significant effect of
hidden-terminal problem on information-theoretic security in cognitive radios.Comment: Submitted to CISS 201
On the Throughput Cost of Physical Layer Security in Decentralized Wireless Networks
This paper studies the throughput of large-scale decentralized wireless
networks with physical layer security constraints. In particular, we are
interested in the question of how much throughput needs to be sacrificed for
achieving a certain level of security. We consider random networks where the
legitimate nodes and the eavesdroppers are distributed according to independent
two-dimensional Poisson point processes. The transmission capacity framework is
used to characterize the area spectral efficiency of secure transmissions with
constraints on both the quality of service (QoS) and the level of security.
This framework illustrates the dependence of the network throughput on key
system parameters, such as the densities of legitimate nodes and eavesdroppers,
as well as the QoS and security constraints. One important finding is that the
throughput cost of achieving a moderate level of security is quite low, while
throughput must be significantly sacrificed to realize a highly secure network.
We also study the use of a secrecy guard zone, which is shown to give a
significant improvement on the throughput of networks with high security
requirements.Comment: Accepted for publication in IEEE Transactions on Wireless
Communication
Waveform Design for Secure SISO Transmissions and Multicasting
Wireless physical-layer security is an emerging field of research aiming at
preventing eavesdropping in an open wireless medium. In this paper, we propose
a novel waveform design approach to minimize the likelihood that a message
transmitted between trusted single-antenna nodes is intercepted by an
eavesdropper. In particular, with knowledge first of the eavesdropper's channel
state information (CSI), we find the optimum waveform and transmit energy that
minimize the signal-to-interference-plus-noise ratio (SINR) at the output of
the eavesdropper's maximum-SINR linear filter, while at the same time provide
the intended receiver with a required pre-specified SINR at the output of its
own max-SINR filter. Next, if prior knowledge of the eavesdropper's CSI is
unavailable, we design a waveform that maximizes the amount of energy available
for generating disturbance to eavesdroppers, termed artificial noise (AN),
while the SINR of the intended receiver is maintained at the pre-specified
level. The extensions of the secure waveform design problem to multiple
intended receivers are also investigated and semidefinite relaxation (SDR) -an
approximation technique based on convex optimization- is utilized to solve the
arising NP-hard design problems. Extensive simulation studies confirm our
analytical performance predictions and illustrate the benefits of the designed
waveforms on securing single-input single-output (SISO) transmissions and
multicasting
A Survey of Physical Layer Security Techniques for 5G Wireless Networks and Challenges Ahead
Physical layer security which safeguards data confidentiality based on the
information-theoretic approaches has received significant research interest
recently. The key idea behind physical layer security is to utilize the
intrinsic randomness of the transmission channel to guarantee the security in
physical layer. The evolution towards 5G wireless communications poses new
challenges for physical layer security research. This paper provides a latest
survey of the physical layer security research on various promising 5G
technologies, including physical layer security coding, massive multiple-input
multiple-output, millimeter wave communications, heterogeneous networks,
non-orthogonal multiple access, full duplex technology, etc. Technical
challenges which remain unresolved at the time of writing are summarized and
the future trends of physical layer security in 5G and beyond are discussed.Comment: To appear in IEEE Journal on Selected Areas in Communication
Power Efficient and Secure Full-Duplex Wireless Communication Systems
In this paper, we study resource allocation for a full-duplex (FD) radio base
station serving multiple half-duplex (HD) downlink and uplink users
simultaneously. The considered resource allocation algorithm design is
formulated as a non-convex optimization problem taking into account minimum
required receive signal-to-interference-plus-noise ratios (SINRs) for downlink
and uplink communication and maximum tolerable SINRs at potential
eavesdroppers. The proposed optimization framework enables secure downlink and
uplink communication via artificial noise generation in the downlink for
interfering the potential eavesdroppers. We minimize the weighted sum of the
total downlink and uplink transmit power by jointly optimizing the downlink
beamformer, the artificial noise covariance matrix, and the uplink transmit
power. We adopt a semidefinite programming (SDP) relaxation approach to obtain
a tractable solution for the considered problem. The tightness of the SDP
relaxation is revealed by examining a sufficient condition for the global
optimality of the solution. Simulation results demonstrate the excellent
performance achieved by the proposed scheme and the significant transmit power
savings enabled optimization of the artificial noise covariance matrix.Comment: 6 pages, invited paper, IEEE Conference on Communications and Network
Security (CNS) 2015 in Florence, Italy, on September 30, 201
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