455 research outputs found
On Secrecy Metrics for Physical Layer Security over Quasi-Static Fading Channels
Theoretical studies on physical layer security often adopt the secrecy outage
probability as the performance metric for wireless communications over
quasi-static fading channels. The secrecy outage probability has two
limitations from a practical point of view: a) it does not give any insight
into the eavesdropper's decodability of confidential messages; b) it cannot
characterize the amount of information leakage to the eavesdropper when an
outage occurs. Motivated by the limitations of the secrecy outage probability,
we propose three new secrecy metrics for secure transmissions over quasi-static
fading channels. The first metric establishes a link between the concept of
secrecy outage and the decodability of messages at the eavesdropper. The second
metric provides an error-probability-based secrecy metric which is typically
used for the practical implementation of secure wireless systems. The third
metric characterizes how much or how fast the confidential information is
leaked to the eavesdropper. We show that the proposed secrecy metrics
collectively give a more comprehensive understanding of physical layer security
over fading channels and enable one to appropriately design secure
communication systems with different views on how secrecy is measured.ARC Discovery Projects Grant DP15010390
Practical LDPC coded modulation schemes for the fading broadcast channel with confidential messages
The broadcast channel with confidential messages is a well studied scenario
from the theoretical standpoint, but there is still lack of practical schemes
able to achieve some fixed level of reliability and security over such a
channel. In this paper, we consider a quasi-static fading channel in which both
public and private messages must be sent from the transmitter to the receivers,
and we aim at designing suitable coding and modulation schemes to achieve such
a target. For this purpose, we adopt the error rate as a metric, by considering
that reliability (security) is achieved when a sufficiently low (high) error
rate is experienced at the receiving side. We show that some conditions exist
on the system feasibility, and that some outage probability must be tolerated
to cope with the fading nature of the channel. The proposed solution exploits
low-density parity-check codes with unequal error protection, which are able to
guarantee two different levels of protection against noise for the public and
the private information, in conjunction with different modulation schemes for
the public and the private message bits.Comment: 6 pages, 4 figures, to be presented at IEEE ICC'14 - Workshop on
Wireless Physical Layer Securit
Physical Layer Security in Wireless Ad Hoc Networks Under A Hybrid Full-/Half-Duplex Receiver Deployment Strategy
This paper studies physical layer security in a wireless ad hoc network with
numerous legitimate transmitter-receiver pairs and eavesdroppers. A hybrid
full-/half-duplex receiver deployment strategy is proposed to secure legitimate
transmissions, by letting a fraction of legitimate receivers work in the
full-duplex (FD) mode sending jamming signals to confuse eavesdroppers upon
their information receptions, and letting the other receivers work in the
half-duplex mode just receiving their desired signals. The objective of this
paper is to choose properly the fraction of FD receivers for achieving the
optimal network security performance. Both accurate expressions and tractable
approximations for the connection outage probability and the secrecy outage
probability of an arbitrary legitimate link are derived, based on which the
area secure link number, network-wide secrecy throughput and network-wide
secrecy energy efficiency are optimized respectively. Various insights into the
optimal fraction are further developed and its closed-form expressions are also
derived under perfect self-interference cancellation or in a dense network. It
is concluded that the fraction of FD receivers triggers a non-trivial trade-off
between reliability and secrecy, and the proposed strategy can significantly
enhance the network security performance.Comment: Journal paper, double-column 12 pages, 9 figures, accepted by IEEE
Transactions on Wireless Communications, 201
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