Analysis of optical power budget in DWDM-FSO link under outdoor atmospheric channel model

In this paper, the effects of atmospheric turbulence on the performance of a hybrid dense wavelength division modulation (DWDM) of free space optical (FSO) communication using advanced modulations are presented. Enhancement in the capacity of transmission and bit rates of the optical networks is obtained by DWDM technology based on FSO communication systems. Proposed modulations are included Return-to-Zero Differential Phase Shift Keying (RZ-DPSK) and Non-Return-to-Zero Differential Phase Shift Keying (NRZ-DPSK) that each of them increases spectrum efficiency. Furthermore, the optical power budget of the proposed system is analytically calculated. Variation of Bit Error Rate and Max quality factor of the designed system with different path distance and input power are obtained considering outdoor atmosphere channel model. As a result, the RZ-DPSK modulation has better performance in comparison to NRZ-DPSK modulation when the atmospheric condition is considered.