Hechmi Saidi and  Noureddine Hamdi,  Performance Analysis of M-Ary Pulse Position Modulation in Multihop Multiple Input Multiple Output-Free Space Optical System over Uncorrelated Gamma-Gamma Atmospheric Turbulence Channels.   journal   = {International Journal of Computer and Information Engineering}, [online]. World Academy of Science, Engineering and Technology.
    February 2019, vol. 147(3). 109 - 113
    [viewed 18 May 2021]. Available from: https://publications.waset.org/pdf/10010121.