研究了Gamma-Gamma大气湍流信道下闪烁和瞄准误差联合效应对自由空间光通信的性能影响。假定自由空间光通信系统采用开关键控(OOK)强度调制直接探测（IM/DD），推导得出了系统的误码率和中断概率闭合表达式，分析了大气湍流、归一化波束宽度、平均发射功率、归一化的抖动标准差、信噪比等参数对系统性能的影响。基于推导的闭合表达式进行了数值模拟，结果表明能够在给定发射功率下通过优化波束宽度使系统性能达到最优。

The performance of free-space optical communication (FSO) with the combined effects from scintillation effect and pointing errors under Gamma-Gamma atmospheric turbulence is investigated. Assuming FSO system uses intensity-modulation/direct detection (IM/DD) with on-off keying (OOK), the novel closed-form expressions of bit error rate (BER) and outage probability for FSO system are derived. How the performance is affected by the atmospheric turbulence and other parameters such as the normalized beamwidth, the average transmitted optical power, the normalized jitter, signal-to-noise ratio is researched. Numerical simulation is further provided to verify the derived analytical expressions. The results show that optimizing the beamwidth can achieve the minimum BER for a given average transmitted optical power.