Date Added: Oct 2010
The performance of Free-Space Optical (FSO) communication suffers from atmospheric turbulence, which mainly results in scintillation and phase fluctuations to optical signal. In this paper, the authors study the Bit Error Rate (BER) performance of coherent FSO system employing phase compensation and spatial diversity. Based on weak fluctuation theory, the amplitude fading and phase fluctuation induced by atmospheric turbulence are assumed to follow log-normal model and Gaussian distribution, respectively. Distinct from previous works, a new closed-form expression for signal fading at the receiver is derived. Then the impact of various compensating parameters is examined on the BER performance of the system, including the normalized receiver aperture diameter and the number of phase compensation modes.