Physical Layer Security Over Mixture Gamma Distributed Fading Channels With Discrete Inputs: A Unified and General Analytical Framework

TL;DR

This paper develops a comprehensive analytical framework to evaluate physical layer security over mixture Gamma fading channels with discrete inputs, providing closed-form expressions and asymptotic analysis of secrecy metrics.

Contribution

It introduces a unified analytical approach for secrecy performance with discrete inputs over mixture Gamma channels, including closed-form and asymptotic expressions.

Findings

Closed-form expressions for ASR and SOP derived

ASR and SOP converge to constants at high SNR

Novel convergence rate expressions obtained

Abstract

Physical layer security is investigated over mixture Gamma (MG) distributed fading channels with discrete inputs. By the Gaussian quadrature rules, closed-form expressions are derived to characterize the average secrecy rate (ASR) and secrecy outage probability (SOP), whose accuracy is validated by numerical simulations. To show more properties of the finite-alphabet signaling, we perform an asymptotic analysis on the secrecy metrics in the large limit of the average signal-to-noise ratio (SNR) of the main channel. Leveraging the Mellin transform, we find that the ASR and SOP converge to some constants as the average SNR increases and we derive novel expressions to characterize the rates of convergence. This work establishes a unified and general analytical framework for the secrecy performance achieved by discrete inputs.