Maximum Secrecy Throughput of MIMOME FSO Communications with Outage Constraints

TL;DR

This paper analyzes the maximum secrecy throughput in MIMOME FSO communication systems with outage constraints, considering different CSI availability scenarios and the impact of multiple apertures on performance.

Contribution

It introduces an analytical framework for effective secrecy throughput in MIMOME FSO systems considering outage constraints and aperture configurations.

Findings

Multiple apertures significantly improve secrecy throughput.

Adaptive scheme outperforms fixed-rate scheme under CSI availability.

Analytical expressions validate the importance of aperture diversity.

Abstract

In this work, we consider a scenario where two multiple-aperture legitimate nodes (Alice and Bob) communicate by means of Free-Space Optical (FSO) communication in the presence of a multiple-aperture eavesdropper (Eve), which is subject to pointing errors. Two different schemes are considered depending on the availability of channel state information (CSI) at Alice: i) the adaptive scheme, where Alice possesses the instantaneous CSI with respect to Bob; ii) the fixed-rate scheme, where such information is not available at Alice. The performance of the aforementioned schemes is evaluated in terms of a recently proposed metric named effective secrecy throughput (EST), which encompasses both the reliability and secrecy constraints. By constraining the system to operate below a given maximum allowed secrecy outage probability, we evaluate the EST analytically and through numerical results, showing that the use of multiple apertures at Alice is very important towards achieving the optimal EST.