Impact of crosstalk and atmospheric turbulence on free space optical communication systems - a hardware emulation

Free space optical (FSO) communication reduces the last-mile bottleneck problem wherever we cannot use fiber-optic links. Performance degradation in the FSO system is mainly due to the atmospheric turbulence effect. To increase the capacity of the system wavelength division multiplexing (WDM) is used. An experimental testbed is set up to investigate the performance of the DWDM-FSO system with and without crosstalk under the influence of atmospheric turbulence. For the study of the system performance, the attenuation values due to scintillation from the existing work are taken as losses. Based on the results, the FSO link length that supports the data transmission is up to 3 km for the tolerable BER of 10⁻⁹. The Q-factor value drops with increasing attenuation and link distance. Q value of the FSO system without crosstalk and with crosstalk at 2 dB is 10.64 and 6.34 for 1 km and 4 km, it is 7.94 and 4.24 respectively.