Average Symbol Error Probability of General-Order Rectangular Quadrature Amplitude Modulation of Optical Wireless Communication Systems Over Atmospheric Turbulence Channels

Average Symbol Error Probability of General-Order Rectangular Quadrature Amplitude Modulation of Optical Wireless Communication Systems Over Atmospheric Turbulence Channels


Abstract—Using an accurate exponential bound for
the Gaussian Q-function, we derive simple approximate
closed-form expressions for the average symbol
error probability (ASEP) of a free-space optical communication
link using subcarrier intensity modulation
(SIM) with general-order rectangular quadrature
amplitude modulation (QAM) over atmospheric
turbulence channels. To model the atmospheric turbulence
conditions, the log-normal and the gammagamma
distribution are used. Extensive numerical
and computer simulation results are presented in order
to verify the accuracy of the proposed mathematical
analysis.