Secrecy Energy Efficiency of MIMOME Wiretap Channels with Full-Duplex Jamming

TL;DR

This paper investigates whether full-duplex jamming can enhance the secrecy energy efficiency of MIMOME wiretap channels, considering residual self-interference and different channel state information scenarios, with iterative solutions and numerical analysis.

Contribution

It formulates and solves new SEE maximization problems for FD MIMOME channels, accounting for residual SI and CSI, providing insights into conditions for effective energy-efficient secure communication.

Findings

Marginal SEE gain in general scenarios with FD jamming.

Significant gain when SI is well mitigated, especially at close distances and high SNR.

Iterative algorithms converge to stationary points for the formulated problems.

Abstract

Full-duplex (FD) jamming transceivers are recently shown to enhance the information security of wireless communication systems by simultaneously transmitting artificial noise (AN) while receiving information. In this work, we investigate if FD jamming can also improve the systems secrecy energy efficiency (SEE) in terms of securely communicated bits-per- Joule, when considering the additional power used for jamming and self-interference (SI) cancellation. Moreover, the degrading effect of the residual SI is also taken into account. In this regard, we formulate a set of SEE maximization problems for a FD multiple-input-multiple-output multiple-antenna eavesdropper (MIMOME) wiretap channel, considering both cases where exact or statistical channel state information (CSI) is available. Due to the intractable problem structure, we propose iterative solutions in each case with a proven convergence to a stationary point. Numerical simulations indicate only a marginal SEE gain, through the utilization of FD jamming, for a wide range of system conditions. However, when SI can efficiently be mitigated, the observed gain is considerable for scenarios with a small distance between the FD node and the eavesdropper, a high Signal-to-noise ratio (SNR), or for a bidirectional FD communication setup.