Analysis of Wavelength Division Multiplexing (WDM) Links bases Radio over free space Optics

Abstract

Radio over free space optics (RoFSO) is an emerging technology in the field of optical communication. Wavelength division multiplexing (WDM) technique can be used to increase the data rates and capacity of RoFSO networks. In this paper, WDM based RoFSO network is studied for a distance of 2 Km on various channel spacing like 25 GHz, 50 GHz and 75 GHz at a data rates of 4Gbps. It is reported that various channel spacing offers bit error rate (BER) in the range of $\mathbf{10}^{-\mathbf{17}}$ to $\mathbf{10}^{-\mathbf{3}}$ for a distance of 1Km to 2 Km. The FSO network with 75 GHz channel spacing produces output with approximately 4dBmhigher power compared to 25 GHz channel spacing. As the Beam divergence is decreased, the RoFSO network performance advances and covers the larger distance. Eye diagrams are also analyzed which shows that higher is the channel spacing lesser is the BER.