Channel capacity and outage probability analysis for free space optical communication over composite channel

Based on the probability density function of the composite channel considering Malaga atmospheric turbulence, pointing error and atmospheric path loss, the asymptotic expressions of channel capacity and outage probability for binary phase shift keying (BPSK) modulation system are derived using Meijer G function. The numerical results show that under the same intensity of turbulence and path loss condition, the optimal performance of channel capacity and outage probability can be obtained by adjusting the jitter standard deviation and beam waist radius when the receiver radius is fixed. Meanwhile, the influence of weather conditions on channel capacity is greater than that of the beam waist radius and jitter standard deviation for the same turbulence distribution. It is illustrated that the optimal system performance can be obtained when w(z)/a = 5 and sigma(s)/a = 1.5 in sunny weather. The channel capacity increases slowly at small signal-to-noise ratio under moderate-strong turbulence, and the stronger the fluctuation variance is, the greater the influence of fog on atmospheric communication.