Performance of Spatial Diversity for FSO Links with Pointing Errors over Malaga Turbulence

Based on the joint probability density function of Malaga atmospheric turbulence and pointing errors, the asymptotic expressions of the average BER for MIMO system with three combing methods including maximum ratio combining(MRC), equal gain combining(EGC) and select combining(SC) are derived. When the receiver radius is fixed, the influence of different beam waist radius and jitter deviation on the average BER of the system is analyzed. Meanwhile, the performance of BER and diversity gain of MRC system is better than that of the other two combining methods When the receiving aperture is 4, the diversity gain of MRC can reach 25dB.