Fig. 1. Light intensity probability density distribution under different optical intensity flicker

Fig. 2. APD receiver architecture diagram

Fig. 3. Flow chart of adaptive control program

Fig. 4. Communication system diagram

Fig. 5. Experimental site map. (a) A side of experimental site map; (b) B side of experimental site map

Fig. 6. Received light signal intensity map for medium turbulence conditions. (a)Without control; (b)with control

Fig. 7. Probability distribution for 500 m without and with gain control. (a)Without control; (b)with control

Fig. 8. Experimental power spectrum for 500 m laser communication

Fig. 9. BERT charts for 500 m communication experiments. (a) Without control; (b) with control

Fig. 10. Test plots for different time periods. (a) Flicker variance test plots; (b) BER test plots