BER performance analysis of APD-based FSO system for optical inter-HAPS link

This paper aims at evaluating bit error rate (BER) performance of optical inter platform link using intensity modulation/direct detection (IM/DD) with on-off keying (OOK) and an avalanche photodiode (APD) receiver based on analyzed theoretically. The atmosphere is not an ideal communication channel. Atmospheric turbulence is one of the main impairment affecting the operation of optical inter platform link. The log normal distribution is used as inter-HAP channel model to describe the effect of atmospheric turbulence. The BER performance is theoretically derived with taking into account various FSO link conditions and receiver parameters. The numerical results ilustrate that the optimal APD gain to achieve minimum BER depends on data rate, the link distance, and atmospheric turbulence strength.