The performance of free-space optical (FSO) links over cascaded Snedecor’s $\mathcal{F}$ turbulence channels with pointing errors is investigated in this paper. To this end, we derive exact analytical expressions for the probability distribution function (PDF) and the cumulative distribution function (CDF) of the irradiance fluctuations in the presence of pointing errors. We also provide exact analytical expressions for the PDF, the CDF, the moment generating function (MGF), the moments, and the scintillation index (SI) of the received signal-to-noise ratio (SNR) assuming both intensity modulation/direct detection (IM/DD) and coherent heterodyne detection. The derived statistical expressions for the SNR are further utilized to derive exact analytical and asymptotic expressions for the outage probability, the average symbol error rate (SER) of various modulation techniques, and the average ergodic capacity. The derived asymptotic expressions give insights into the diversity gain of the system. The derived expressions are verified by Monte-Carlo simulations.

级联 Snedecor 上的自由空间光 (FSO) 链路的性能$\mathcal{F}$本文研究了具有指向误差的湍流通道。为此，我们推导出了存在指向误差时辐照度波动的概率分布函数 (PDF) 和累积分布函数 (CDF) 的精确解析表达式。假设强度调制/直接检测，我们还提供了接收信噪比 (SNR) 的 PDF、CDF、矩生成函数 (MGF)、矩和闪烁指数 (SI) 的精确解析表达式(IM/DD) 和相干外差检测。导出的 SNR 统计表达式进一步用于导出中断概率、各种调制技术的平均符号错误率 (SER) 和平均遍历容量的精确解析和渐近表达式。派生的渐近表达式可以深入了解系统的多样性增益。派生的表达式通过蒙特卡洛模拟进行验证。