1,806 research outputs found
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
An Overview of Physical Layer Security with Finite Alphabet Signaling
Providing secure communications over the physical layer with the objective of achieving 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 discuss some open problems and directions for future research
Resource Allocation for Secure Gaussian Parallel Relay Channels with Finite-Length Coding and Discrete Constellations
We investigate the transmission of a secret message from Alice to Bob in the
presence of an eavesdropper (Eve) and many of decode-and-forward relay nodes.
Each link comprises a set of parallel channels, modeling for example an
orthogonal frequency division multiplexing transmission. We consider the impact
of discrete constellations and finite-length coding, defining an achievable
secrecy rate under a constraint on the equivocation rate at Eve. Then we
propose a power and channel allocation algorithm that maximizes the achievable
secrecy rate by resorting to two coupled Gale-Shapley algorithms for stable
matching problem. We consider the scenarios of both full and partial channel
state information at Alice. In the latter case, we only guarantee an outage
secrecy rate, i.e., the rate of a message that remains secret with a given
probability. Numerical results are provided for Rayleigh fading channels in
terms of average outage secrecy rate, showing that practical schemes achieve a
performance quite close to that of ideal ones
Learning End-to-End Codes for the BPSK-constrained Gaussian Wiretap Channel
Finite-length codes are learned for the Gaussian wiretap channel in an
end-to-end manner assuming that the communication parties are equipped with
deep neural networks (DNNs), and communicate through binary phase-shift keying
(BPSK) modulation scheme. The goal is to find codes via DNNs which allow a pair
of transmitter and receiver to communicate reliably and securely in the
presence of an adversary aiming at decoding the secret messages. Following the
information-theoretic secrecy principles, the security is evaluated in terms of
mutual information utilizing a deep learning tool called MINE (mutual
information neural estimation). System performance is evaluated for different
DNN architectures, designed based on the existing secure coding schemes, at the
transmitter. Numerical results demonstrate that the legitimate parties can
indeed establish a secure transmission in this setting as the learned codes
achieve points on almost the boundary of the equivocation region
On the Secrecy Performance of Interference Exploitation with PSK: A non-Gaussian Signaling Analysis
Interference exploitation has recently been shown to provide significant security benefits in multi-user communication systems. In this technique, the known interference is designed to be constructive to the legitimate users and disruptive to the malicious receivers. Accordingly, this paper analyzes the secrecy performance of constructive interference (CI) precoding technique in multi-user multiple-input single-output (MU-MISO) systems with phase-shift-keying (PSK) signals and in the presence of multiple passive eavesdroppers. The secrecy performance of CI technique is comprehensively investigated in terms of symbol error probability (SEP), secrecy sum-rate, and intercept probability (IP). Firstly, new and exact analytical expressions for the average SEP of the legitimate users and the eavesdroppers are derived. In addition, for simplicity and in order to provide more insights, very accurate approximations of the average SEPs are presented in closed-form. Departing from classical Gaussian rate analysis, we employ finite constellation rate expressions to investigate the secrecy sum-rate. In this regard, closed-form analytical expression of the ergodic secrecy sum-rate is obtained. Then, based on the new secrecy sum-rate expression we propose adaptive modulation (AM) scheme with the aim to enhance the secrecy performance. Finally, we present analytical expressions of the IP with fixed and adaptive modulations. The analytical and simulation results demonstrate that, the interference exploitation technique can provide additional up to 17dB gain in the transmit SNR in terms of SEP, and up to 10dB gain in terms of the secrecy sum-rate and the IP, compared to the conventional interference suppression technique. Furthermore, significant performance improvement up to 66% can be achieved with the proposed AM scheme
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