Performance Analysis of 25 Gbps DP-QPSK Based CO-OFDM-FSO Link Incorporating Spatial Diversity under Climate Conditions and Atmospheric Turbulence

Abstract

Attenuation caused by various weather conditions and atmospheric turbulence significantly reduces the performance and reliability of free space optics (FSO) link. This paper employs simulations to analyze the signal quality of the proposed FSO link under various climate conditions. The performance analysis and parametric evaluation of the proposed 25 Gbps DP-QPSK based CO-OFDM FSO link is carried out with and without the spatial diversity technique. Also, we have compared the proposed FSO link with the 16-QAM-based OFDM FSO link for vivid atmospheric conditions. The simulation results are analyzed in terms of key performance metrics such as bit error rate (BER), signalto-noise ratio (SNR), link distance, received power, and reliability. The results show that the FSO link with spatial diversity is more effective towards mitigating the adverse effects of atmospheric attenuation and turbulence in comparison with FSO link without diversity and 16-QAM OFDM-based FSO link. In total, this results in lower BER, higher SNR, improved received power, and increased reliable distance for practical FSO communication system.