121 research outputs found
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
Artificial-Noise-Aided Secure Multi-Antenna Transmission with Limited Feedback
We present an optimized secure multi-antenna transmission approach based on
artificial-noise-aided beamforming, with limited feedback from a desired
single-antenna receiver. To deal with beamformer quantization errors as well as
unknown eavesdropper channel characteristics, our approach is aimed at
maximizing throughput under dual performance constraints - a connection outage
constraint on the desired communication channel and a secrecy outage constraint
to guard against eavesdropping. We propose an adaptive transmission strategy
that judiciously selects the wiretap coding parameters, as well as the power
allocation between the artificial noise and the information signal. This
optimized solution reveals several important differences with respect to
solutions designed previously under the assumption of perfect feedback. We also
investigate the problem of how to most efficiently utilize the feedback bits.
The simulation results indicate that a good design strategy is to use
approximately 20% of these bits to quantize the channel gain information, with
the remainder to quantize the channel direction, and this allocation is largely
insensitive to the secrecy outage constraint imposed. In addition, we find that
8 feedback bits per transmit antenna is sufficient to achieve approximately 90%
of the throughput attainable with perfect feedback.Comment: to appear in IEEE Transactions on Wireless Communication
An Overview of Physical Layer Security with Finite-Alphabet Signaling
Providing secure communications over the physical layer with the objective of
achieving perfect secrecy without requiring a secret key has been receiving
growing attention within the past decade. The vast majority of the existing
studies in the area of physical layer security focus exclusively on the
scenarios where the channel inputs are Gaussian distributed. However, in
practice, the signals employed for transmission are drawn from discrete signal
constellations such as phase shift keying and quadrature amplitude modulation.
Hence, understanding the impact of the finite-alphabet input constraints and
designing secure transmission schemes under this assumption is a mandatory step
towards a practical implementation of physical layer security. With this
motivation, this article reviews recent developments on physical layer security
with finite-alphabet inputs. We explore transmit signal design algorithms for
single-antenna as well as multi-antenna wiretap channels under different
assumptions on the channel state information at the transmitter. Moreover, we
present a review of the recent results on secure transmission with discrete
signaling for various scenarios including multi-carrier transmission systems,
broadcast channels with confidential messages, cognitive multiple access and
relay networks. Throughout the article, we stress the important behavioral
differences of discrete versus Gaussian inputs in the context of the physical
layer security. We also present an overview of practical code construction over
Gaussian and fading wiretap channels, and we discuss some open problems and
directions for future research.Comment: Submitted to IEEE Communications Surveys & Tutorials (1st Revision
On the Design of Artificial-Noise-Aided Secure Multi-Antenna Transmission in Slow Fading Channels
In this paper, we investigate the design of artificial-noise-aided secure
multi-antenna transmission in slow fading channels. The primary design concerns
include the transmit power allocation and the rate parameters of the wiretap
code. We consider two scenarios with different complexity levels: i) the design
parameters are chosen to be fixed for all transmissions, ii) they are
adaptively adjusted based on the instantaneous channel feedback from the
intended receiver. In both scenarios, we provide explicit design solutions for
achieving the maximal throughput subject to a secrecy constraint, given by a
maximum allowable secrecy outage probability. We then derive accurate
approximations for the maximal throughput in both scenarios in the high
signal-to-noise ratio region, and give new insights into the additional power
cost for achieving a higher security level, whilst maintaining a specified
target throughput. In the end, the throughput gain of adaptive transmission
over non-adaptive transmission is also quantified and analyzed.Comment: to appear in IEEE Transactions on Vehicular Technolog
Jamming Games in the MIMO Wiretap Channel With an Active Eavesdropper
This paper investigates reliable and covert transmission strategies in a
multiple-input multiple-output (MIMO) wiretap channel with a transmitter,
receiver and an adversarial wiretapper, each equipped with multiple antennas.
In a departure from existing work, the wiretapper possesses a novel capability
to act either as a passive eavesdropper or as an active jammer, under a
half-duplex constraint. The transmitter therefore faces a choice between
allocating all of its power for data, or broadcasting artificial interference
along with the information signal in an attempt to jam the eavesdropper
(assuming its instantaneous channel state is unknown). To examine the resulting
trade-offs for the legitimate transmitter and the adversary, we model their
interactions as a two-person zero-sum game with the ergodic MIMO secrecy rate
as the payoff function. We first examine conditions for the existence of
pure-strategy Nash equilibria (NE) and the structure of mixed-strategy NE for
the strategic form of the game.We then derive equilibrium strategies for the
extensive form of the game where players move sequentially under scenarios of
perfect and imperfect information. Finally, numerical simulations are presented
to examine the equilibrium outcomes of the various scenarios considered.Comment: 27 pages, 8 figures. To appear, IEEE Transactions on Signal
Processin
Artificial Noise: Transmission Optimization in Multi-Input Single-Output Wiretap Channels
We analyze and optimize the secrecy performance of
artificial noise (AN) in multi-input single-output wiretap channels
with multiple antennas at the transmitter and a single antenna at
the receiver and the eavesdropper. We consider two transmission
schemes: 1) an on-off transmission scheme with a constant secrecy
rate for all transmission periods, and 2) an adaptive transmission
scheme with a varying secrecy rate during each transmission
period. For the on-off transmission scheme, an easy-to-compute
expression is derived for the hybrid outage probability, which
allows us to evaluate the transmission outage probability and the
secrecy outage probability. For the adaptive transmission scheme
where transmission outage does not occur, we derive a closedform
expression for the secrecy outage probability. Using these
expressions, we determine the optimal power allocation between
the information signal and the AN signal and also determine the
optimal secrecy rate such that the effective secrecy throughput
is maximized for both transmission schemes. We show that the
maximum effective secrecy throughput requires more power to
be allocated to the AN signal when the quality of the transmitterreceiver
channel or the transmitter-eavesdropper channel improves.
We also show that both transmission schemes achieve
a higher maximum effective secrecy throughput while incurring
a lower secrecy outage probability than existing schemes.ARC Discovery Projects Grant DP150103905
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