误码率(BER)是衡量无线光通信系统设计优劣的重要指标，如何正确统计误码性能显得尤为重要。利用Matlab软件，研究基于蒙特卡罗仿真实现无线光通信系统误码性能分析的方法。介绍了无线光通信系统以及利用蒙特卡罗仿真进行性能估计的原理；研究了误码性能仿真方法，详细地给出了仿真中的信源产生方法、信道模型、信噪比参数计算方法、误码率统计方法等，并给出了部分核心Matlab程序；给出了基于低密度奇偶校验(LDPC)码、脉冲位置调制(PPM)的无线光通信系统仿真图，详细介绍了各仿真参数的设置，并在不同天气和不同信噪比条件下统计了系统性能。统计结果表明，此性能分析方法准确可行。

Bit error rate (BER) is an important evaluation index of free space optical communication (FSO), and how to exactly get the BER statistics is rather important. We study the technique of analyzing the BER of FSO based on Monte Carlo simulation using Matlab software. The FSO system and the principle of Monte Carlo simulation are introduced. The method of getting the BER statistics is researched, and the method of generating information source, the channel model, and the calculation of signal-to-noise ratio (SNR) parameter for simulation are given detailedly. Moreover, part of the core Matlab program is presented. The modeling and simulation based on the low-density parity check (LDPC) code and pulse position modulation (PPM) are implementted. The analysis results under different conditions of weather and signal-to-noise ratio indicate the this method is accurate and pratical.