Improving Anti-Eavesdropping Ability without Eavesdropper's CSI: A Practical Secure Transmission Design Perspective

TL;DR

This paper proposes a practical method to enhance secure wireless transmissions without requiring knowledge of the eavesdropper's channel, introducing an ECSI-irrelevant metric to quantify anti-eavesdropping ability and optimize security.

Contribution

It introduces an ECSI-irrelevant metric for anti-eavesdropping ability and develops transmission schemes that maximize this metric without needing eavesdropper's CSI.

Findings

Maximizing anti-eavesdropping ability minimizes secrecy outage probability.

The proposed schemes achieve optimal encoding and power allocation.

Anti-eavesdropping ability effectively assesses security without ECSI.

Abstract

This letter studies the practical design of secure transmissions without knowing eavesdropper's channel state information (ECSI). An ECSI-irrelevant metric is introduced to quantize the intrinsic anti-eavesdropping ability (AEA) that the transmitter has on confronting the eavesdropper via secrecy encoding together with artificial-noise-aided signaling. Non-adaptive and adaptive transmission schemes are proposed to maximize the AEA with the optimal encoding rates and power allocation presented in closed-form expressions. Analyses and numerical results show that maximizing the AEA is equivalent to minimizing the secrecy outage probability (SOP) for the worst case by ignoring eavesdropper's receiver noise. Therefore, the AEA is a useful alternative to the SOP for assessing and designing secure transmissions when the ECSI cannot be prior known.