Performance analysis of FSO links employing a transmit and receive diversity-based operating system under M?laga turbulence channels with pointing errors

This paper represents the performance analysis of a transmit and receive diversitycode (STBC) and the switch-and-examine combining (SEC) technique at the transmitter end receiver section. The generalized Malaga statistical distribution has been considered to realize the effect of atmospheric turbulence with pointing error. A new unified analytical framework has been employed to obtain the closed-form expressions for various performance measures like outage probability, average bit error rate (BER), and average capacity of the said system. The results indicate that the performance gets better as the number of receiving antennas increases but only within the low signal to noise radio (SNR) region. Further, the optimum switching threshold scheme has been implemented for this proposed multi input multi output (MIMO) FSO system to achieve improved and optimum performances. However, applying the optimum switching threshold for SEC, the performance improvement is observed in the system's outage and BER performance but not significantly in average capacity. Finally, the derived analytical expressions for each performance metric are validated through the corresponding Monte-Carlo simulations presented in various graphical plots.