Effects of pointing errors on average capacity of FSO links over gamma-gamma turbulence channel

In this paper, we derive new closed-form expression for the average channel capacity of the free space optical (FSO) system with intensity-modulation/direct detection (IM/DD). The intensity fluctuations at receiver are described by combined model which assumes turbulence effects, pointing errors and path loss. The numerical results are presented. The effects of normalized jitter variance, propagation distance and turbulence strength are discussed.