M.R.  Kavitha, K. Parimala  Geetha, 
    A Gamma-Exponential Distribution Channel Model for Turbulence in
Free Space Optical Communication,
    Asian Journal of Information Technology,
    Volume 15,Issue 20,
    2016,
    Pages 4011-4019,
    ISSN 1682-3915,
    ajit.2016.4011.4019,
    (https://makhillpublications.co/view-article.php?doi=ajit.2016.4011.4019)
    Abstract: Now a day’s various type channel modeling are proposed in communication medium. In this paper introduces a new channel model known as gamma-exponential distribution for turbulence vanishing in free space optical communication. The proposed model acquires the probability density function and bit error rate of received Quadrature Amplitude Modulation (QAM) modulated optical power in Free Space Optical and (FSO) communication. This method acts well under weak, moderate and strong turbulence conditions. This model is related with existing channel models, Rayleigh fading channel model, gamma distribution channel model and gamma-gamma distribution channel model.
    Keywords: Gamma channel;QAM;free space optical;rayleigh fading;turbulence