摘要
This paper investigates the reliability problem of airborne free-space optical(FSO)communications,and a hybrid FSO/radio frequency(RF)communication system with parallel transmission is proposed,where the data stream is transmitted over both FSO and RF links simultaneously.Further,to combat channel fading,maximal ratio combining is utilized at the receiver for combining received signals from both links.The performances of the proposed system are analytically derived in terms of the outage probability and the average bite-error rate(BER).Numerical results show that the proposed hybrid FSO/RF system with parallel transmission outperforms a single airborne FSO or a single RF link,which provides technical guidance for designing reliable high-speed airborne communication systems.