Secure HARQ-IR-Aided Terahertz Communications

TL;DR

This paper introduces a secure THz communication scheme using HARQ-IR, deriving outage probabilities and optimizing throughput while ensuring security against eavesdroppers.

Contribution

It proposes a novel secure HARQ-IR scheme for THz communications, with analytical derivations and a robust rate adaptation policy for enhanced security and throughput.

Findings

Closed-form connection and secrecy outage probabilities derived.

Asymptotic analysis of outage probabilities in high SNR regimes.

A rate adaptation policy maximizes throughput under security constraints.

Abstract

Terahertz (THz) communication is one of the most promising candidates to accommodate high-speed mobile data services. This paper proposes a secure hybrid automatic repeat request with incremental redundancy (HARQ-IR) aided THz communication scheme, where the transmission secrecy is ensured by confusing the eavesdropper with dummy messages. The connection and secrecy outage probabilities are then derived in closed-form. Besides, the tail behaviour of the connection outage probability in high signal-to-noise ratio (SNR) is examined by carrying out the asymptotic analysis, and the upper bound of the secrecy outage probability is obtained in a simple form by capitalizing on large deviations. With these results, we take a step further to investigate the secrecy long term average throughput (LTAT). By noticing that HARQ-IR not only improves the reliability of the legitimate user, but also increases the probability of being eavesdropped, a robust rate adaption policy is finally proposed to maximize the LTAT while restricting the connection and secrecy outage probabilities within satisfactory requirements.