In this paper, the impact of in-(I) phase/quadrature-(Q) phase imbalance (IQI) in mixed radio frequency/free space optical (RF/FSO) cooperative relaying systems is studied. The RF link has been assumed to undergo Nakagami-$m$ distributed fading, while the FSO link is under the influence of atmospheric turbulence modeled by the Malaga irradiance model with pointing errors. The FSO model accounts for both kinds of optical demodulation schemes, i.e., intensity modulation direct detection (IM/DD) and coherent demodulation. For the considered system, the impact of hardware IQI has been taken into account in order to derive closed-form expressions for the outage probability and ergodic capacity of the amplify-and-forward (AF) relaying system. These expressions have been further presented in terms of elementary functions for high signal-to-noise ratio (SNR) region of operation. The presented analytical framework has been verified by Monte-Carlo simulations to illustrate the impact of various parameters on the performance of the considered system.

在本文中，研究了 in-(I) 相位/正交-(Q) 相位不平衡 (IQI) 在混合射频/自由空间光 (RF/FSO) 协作中继系统中的影响。假定 RF 链路经过 Nakagami-$米$分布衰落，而 FSO 链路受到由具有指向误差的马拉加辐照度模型建模的大气湍流的影响。FSO 模型考虑了两种光解调方案，即强度调制直接检测（IM/DD）和相干解调。对于所考虑的系统，已经考虑了硬件 IQI 的影响，以推导出放大转发 (AF) 中继系统的中断概率和遍历容量的闭式表达式。这些表达式已经根据高信噪比 (SNR) 操作区域的基本函数进一步呈现。所提出的分析框架已通过蒙特卡罗模拟验证，以说明各种参数对所考虑系统性能的影响。