Performance of a Threshold-based WDM and ACM for FSO Communication between Mobile Platforms in Maritime Environments

TL;DR

This paper analyzes the performance of a threshold-based optical signal selection scheme for WDM and ACM in maritime FSO communication, deriving new formulas and demonstrating improved spectral efficiency under challenging conditions.

Contribution

It introduces a new closed-form PDF for FSO channels affected by fog and pointing errors and evaluates the benefits of WDM and ACM in maritime environments.

Findings

Higher average spectral efficiency with TMOS-based WDM and ACM.

Increased detection probability at low SNR levels.

WDM and ACM are effective in dynamic maritime channels.

Abstract

In this study, we statistically analyze the performance of a threshold-based multiple optical signal selection scheme (TMOS) for wavelength division multiplexing (WDM) and adaptive coded modulation (ACM) using free space optical (FSO) communication between mobile platforms in maritime environments with fog and 3D pointing errors. Specifically, we derive a new closed-form expression for a composite probability density function (PDF) that is more appropriate for applying various algorithms to FSO systems under the combined effects of fog and pointing errors. We then analyze the outage probability, average spectral efficiency (ASE), and bit error rate (BER) performance of the conventional detection techniques (i.e., heterodyne and intensity modulation/direct detection). The derived analytical results were cross-verified using Monte Carlo simulations. The results show that we can obtain a higher ASE performance by applying TMOS-based WDM and ACM and that the probability of the beam being detected in the photodetector increased at a low signal-to-noise ratio, contrary to conventional performance. Furthermore, it has been confirmed that applying WDM and ACM is suitable, particularly in maritime environments where channel conditions frequently change.