Bit Error Rate Analysis of Different Modulation Schemes in Free Space Optics Link using Gamma-Gamma Turbulence Model

Abstract

Free Space Optical (FSO) link using gamma-gamma channel model has been studied in this paper. Comparison of the probability density function of gamma-gamma distribution under weak and strong turbulence regime has been performed. Performance of Bit error rate (BER) using different subcarrier-intensity modulation (SIM) schemes such as binary phase shift keying (BPSK), M-ary phase shift keying (M-PSK) and quadrature amplitude modulation (QAM) have been also investigated. Using MATLAB software, the BER is plotted with respect to normalized signal to noise ratio (SNR) and the link distance. All the analysis has been done using the Gamma-Gamma distribution model. In this work we found that the effectiveness of each modulation technique depends on the environment.