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.

翻译：本研究对海上雾霾与三维指向误差环境下移动平台间自由空间光通信中基于阈值的多光信号选择方案在波分复用与自适应编码调制中的性能进行了统计分析。具体而言，我们推导了一种新的复合概率密度函数闭式表达式，该表达式更适用于在雾霾与指向误差共同影响下对自由空间光通信系统应用各类算法。随后，我们分析了传统检测技术（即外差检测与强度调制/直接检测）的中断概率、平均频谱效率及误码率性能。推导出的解析结果通过蒙特卡洛仿真进行了交叉验证。结果表明：通过应用基于多光信号选择方案的波分复用与自适应编码调制可获得更高的平均频谱效率；与传统性能表现相反，在低信噪比条件下光束被光电探测器探测到的概率有所提升。此外，研究证实波分复用与自适应编码调制的应用尤其适用于信道条件频繁变化的海上环境。