BER Analysis of Lognormal and Gamma-Gamma Turbulence Channel under different modulation Techniques for FSO System

FSO Communication system is basically a line of sight communication of light in visible or infrared region. It is also considered as solution to the last mile problem incorporating various advantages over RF Communication. In this paper, various modulation techniques have been discussed over commonly used Lognormal and Gamma-Gamma turbulence. The different modulation techniques are discussed for all turbulence regimes. To obtain an optimum BER, M-ary signals require lesser SNR compared to other modulation techniques for all turbulence regimes. The performance of FSO system can further be improved by increasing the value of M.