Secrecy Performance for Finite-Alphabet Inputs Over Fluctuating Two-Ray Channels in FDA Communications

TL;DR

This paper analyzes the secrecy performance of FDA communication systems with finite-alphabet inputs over fluctuating two-ray channels, providing closed-form expressions and asymptotic analysis to inform practical system design.

Contribution

It derives closed-form expressions for secrecy metrics and compares finite-alphabet inputs with Gaussian inputs in FDA systems over FTR channels, highlighting practical implications.

Findings

Closed-form expressions for ASR and SOP are derived.

Asymptotic analysis reveals the secrecy performance gap at high SNR.

Finite-alphabet inputs offer practical insights for FDA system security.

Abstract

To provide system design insights for practical communication systems equipped with the frequency diverse array (FDA), this paper investigates the secrecy performance of FDA systems exploiting finite-alphabet inputs over fluctuating two-ray (FTR) fading channels. More specifically, closed-form expressions for the average secrecy rate (ASR) and the secrecy outage probability (SOP) are derived, while their correctness is confirmed by numerical simulations. In addition, we perform asymptotic analysis to quantify the secrecy performance gap between Gaussian and finite-alphabet inputs, for a sufficiently large average signal-to-noise ratio (SNR) of the main channel. Compared with Gaussian inputs-based research, this letter focuses on practical scenarios which sheds lights on properties of FDA systems.