An Overview of Physical Layer Security with Finite Alphabet Signaling
Artikel i vetenskaplig tidskrift, 2018

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.

wiretap channel

coset coding

spread spectrum techniques

5G systems


spatial modulation



finite-alphabet inputs

cooperative communications

cross-layer security.


artificial noise

millimeter wave

Physical layer security

channel state information


convolutional codes

channel reciprocity

turbo codes


Sina Rezaei Aghdam

Chalmers, Elektroteknik, Kommunikations- och antennsystem, Kommunikationssystem

Alireza Nooraiepour

Rutgers, The State University of New Jersey

Tolga M. Duman

Bilkent Universitesi

IEEE Communications Surveys and Tutorials

1553-877X (ISSN)


Informations- och kommunikationsteknik







Mer information

Senast uppdaterat