Abstract The performance of a generalized mixed free-space-optical (FSO)/millimeter (mm)-wave radio-frequency (RF) two-hop link model is investigated in this work. The first-hop FSO channel considers the influence of path loss, atmospheric turbulence which is modeled by the gamma–gamma (GG)-distribution, and generalized misalignment errors which incorporate the effects of non-zero boresight errors, different jitter standard deviations along the horizontal and vertical directions, and correlation between the horizontal and vertical displacements. The second-hop RF link is modeled by an extended-generalized-K (EGK) distribution which is a versatile distribution and can characterize various fading conditions in mm-wave wireless channels where the transmission frequency is in excess of 60 GHz, and considers non-homogeneous propagation, interference effects due to multiuser transmission, multipath fading and shadowing effects observed in mm-wave RF wireless channels. The considered system employs fixed-gain amplify-and-forward (AF) relay-assisted transmission. The statistical characteristic for the end-to-end SNR, i.e., cumulative distribution function (cdf), is obtained for the considered system model in this work. Based on the obtained result for cdf, the outage and error performance is evaluated, and closed form expressions for the same are derived. The derived analytical results have been illustrated through numerical plots.

中文翻译：

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通过广义未对准和射频衰落分布建模的 AF 中继混合 FSO/毫米波射频链路的性能评估

摘要 本文研究了广义混合自由空间光学 (FSO)/毫米 (mm) 波射频 (RF) 两跳链路模型的性能。第一跳 FSO 信道考虑了路径损耗的影响、由伽马-伽马 (GG) 分布建模的大气湍流和广义未对准误差的影响，这些误差包括非零视轴误差、沿线的不同抖动标准偏差的影响。水平和垂直方向，以及水平和垂直位移之间的相关性。第二跳 RF 链路由扩展广义 K (EGK) 分布建模，该分布是一种通用分布，可以表征传输频率超过 60 GHz 的毫米波无线信道中的各种衰落条件，并考虑非-均匀传播，由于在毫米波 RF 无线信道中观察到的多用户传输、多径衰落和阴影效应造成的干扰效应。所考虑的系统采用固定增益放大转发 (AF) 中继辅助传输。端到端 SNR 的统计特性，即累积分布函数 (cdf)，是在这项工作中为所考虑的系统模型获得的。根据获得的 cdf 结果，评估中断和错误性能，并推导出其封闭形式表达式。导出的分析结果已通过数值图说明。端到端 SNR 的统计特性，即累积分布函数 (cdf)，是在这项工作中为所考虑的系统模型获得的。根据获得的 cdf 结果，评估中断和错误性能，并推导出其封闭形式表达式。导出的分析结果已通过数值图说明。端到端 SNR 的统计特性，即累积分布函数 (cdf)，是在这项工作中为所考虑的系统模型获得的。根据获得的 cdf 结果，评估中断和错误性能，并推导出其封闭形式表达式。导出的分析结果已通过数值图说明。