On the Design of Artificial-Noise-Aided Secure Multi-Antenna Transmission in Slow Fading Channels

TL;DR

This paper explores the optimal design of artificial-noise-aided secure multi-antenna transmission in slow fading channels, focusing on power allocation and rate parameters to maximize throughput under secrecy constraints.

Contribution

It provides explicit design solutions for fixed and adaptive transmission scenarios, including high-SNR approximations and analysis of throughput gains from adaptation.

Findings

Explicit solutions for throughput maximization under secrecy constraints.

High-SNR approximations for throughput in both scenarios.

Quantification of throughput gains from adaptive transmission.

Abstract

In this paper, we investigate the design of artificial-noise-aided secure multi-antenna transmission in slow fading channels. The primary design concerns include the transmit power allocation and the rate parameters of the wiretap code. We consider two scenarios with different complexity levels: i) the design parameters are chosen to be fixed for all transmissions, ii) they are adaptively adjusted based on the instantaneous channel feedback from the intended receiver. In both scenarios, we provide explicit design solutions for achieving the maximal throughput subject to a secrecy constraint, given by a maximum allowable secrecy outage probability. We then derive accurate approximations for the maximal throughput in both scenarios in the high signal-to-noise ratio region, and give new insights into the additional power cost for achieving a higher security level, whilst maintaining a specified target throughput. In the end, the throughput gain of adaptive transmission over non-adaptive transmission is also quantified and analyzed.