Performance analysis of FSO systems in lognormal-Rician turbulence with pointing errors

In this paper, an approximate closed-form probability density function expression for the lognormal-Rician atmospheric turbulence with generalized pointing errors model is developed using a series representation. To reveal the importance of the proposed approximation, the approximate analytic expressions of the ergodic capacity and outage probability are derived for free-space optical (FSO) systems over such channels. Also, by using the obtained asymptotic ergodic capacity expressions, the impact of pointing errors on the ergodic capacity is considerably mitigated by selecting the optimum beam width at the transmitter side. All of the derived analytical results are confirmed by Monte Carlo simulation results.