Investigation of Figure of Merits for 256qam-Fso Link at Diverse Climate Conditions

Abstract

Free space optical communication (FSO) has become an emerging broadband network. Even with the potential advantages of FSO technology, atmospheric turbulence, cloud-induced fading, and other environmental conditions such as fog, aerosol, temperature changes, storms, heavy rain, aiming inaccuracy, and scintillation reduce the performance of the faithful transmission. Different schemes have been suggested for performance improvement for the free-space optical link. This article presented the 256QAM-FSO link, investigated the effect of different weather conditions on the received signals, and summarised bit error rate, error vector magnitude, symbol error rate, power spectral density, and constellation diagram with and without atmosphere turbulence scenarios. The power spectral density of the output signal is a maximum of -56dBm in the moderate haze and a minimum of -70dBm for heavy fog conditions, whereas the maximum output power is achieved at -53.70 dB in the case of low haze, and the minimum output power is achieved -102.22dB in case of moderate haze condition. Error vector magnitude suffers more from the haze condition, and SER varies from 0.734 to 0.758. The maximum bit rate obtained for moderate haze is 1941. With the advanced modulation scheme, the 256QAM -FSO link will provide wide bandwidth, which is helpful for outdoor and indoor services, terrestrial transmission and mile solution, and so on.

Keywords: Free space optics, 256 QAM, Climate Condition, Figure of Merits, Attenuation.