Analytical Performance Evaluation of a LDPC and STBC Coded FDM FSO Communication System under Turbulent Atmospheric Channel

Free space Optical (FSO) communication systems are severely laid down with the weather situations. Atmospheric turbulence is one of the essential facts that degrade the overall performance of a FSO system even under smooth sky circumstance. Coding is one of the techniques that may be applied to improve the overall performance of a communication system. Moreover, it's miles very crucial to apply proper coding approach to enhance the performance. This paper affords an analytical method to evaluate the overall performance of LDPC and STBC coded FSO communication system under the impact of strong atmospheric turbulence. Evaluation is done to find the expressions for the output photodetector current and signal to noise power ratio. The average bit error rate is evaluated numerically thinking about gamma-gamma distributions for the atmospheric turbulence. Analytical results show that for similar type of system configuration in FSO, STBC provides better performances than LDPC code.