BER analysis of OOK and DPSK schemes in gamma-gamma turbulence channel with PIN and APD photodetector

FSO communication is the line of sight communication mainly considered as next generation high speed wireless communication technology because of its numerous advantages over RF communication like for instance; high data rate in the order of Gbps, large bandwidth, unlicensed spectrum accessibility as well as good secrecy against the eavesdroppers. There are number of modulation schemes that could be applied to optical channels. In this paper, we present a comparative analysis of two modulation schemes i.e. OOK and DPSK in terms of BER for Gamma-Gamma atmospheric model in the presence of PIN and APD photodetector used alternatively. For both the schemes, set-up with APD photodetector shows better performance as PIN photodetector in the said atmospheric channel. The above simulation is performed under Optiwave system environment.