Maximum Likelihood Estimation of the Lognormal-Rician FSO Channel Model

In this letter, the on-going challenges are addressed for the application of the lognormal-Rician turbulence model to free-space optical communication systems. Maximum likelihood estimation is applied to characterize the lognormal-Rician turbulence model parameters, and the expectation-maximization algorithm is used to compute maximum likelihood estimates of the unknown parameters. The performance is investigated, by way of the mean square error, and it is found that the proposed technique can accurately characterize free-space optical communication channels over a wide range of turbulence conditions, with reduced demand on the quantity of data samples.