Outage Analysis of a SIMO FSO System Over an Arbitrarily Correlated $\mathcal {M}$ -Distributed Channel

In this letter, we present the outage performance analysis of a single-input multiple-output free-space optical system with selection combining over an arbitrarily correlated Málaga <inline-formula> <tex-math notation="LaTeX">$\mathcal {(M)}$ </tex-math></inline-formula>-distributed channel. A novel and generalized analytical expression for the joint probability density function of the received signal-to-noise ratio, using Green’s matrix approximation, is derived in the form of power series. The proposed expression is valid for an arbitrary correlation model and can be mapped to most of the other existing distributions characterizing different atmospheric turbulence conditions. Moreover, mapping of correlated <inline-formula> <tex-math notation="LaTeX">$\mathcal {M}$ </tex-math></inline-formula>-distribution to correlated Gamma–Gamma and <inline-formula> <tex-math notation="LaTeX">$K$ </tex-math></inline-formula> distributions is illustrated with the help of derived analytical results; correctness of the mapped distributions is verified by simulation.