Fig. 1. Schematic diagram of atmospheric MIMO optical channel

Fig. 2. Frame structure for signal transmission between legitimate parties

Fig. 3. Flow chart of secret-key extraction

Fig. 4. Pearson correlation coefficient between and at different moving average window sizes不同移动平均窗口下与的皮尔逊相关系数

Fig. 5. Schematic diagram of encoding mapping with Q_l =8

Fig. 6. Comparison chart of initial key disagreement rate for different schemes