BER Performance Analysis of OFDM Based Free Space Optical Communication System using µ-Law and A-Law Methods

The Free Space Optics (FSO) is considered as a last mile olution for optical fiber backbone networks that potentially solve the issues like high transmission capacity and ease of deployment of wireless links. In Wireless Local Area Network (WLAN), Orthogonal Frequency Division Multiplexing (OFDM) mitigates the effects of multipath propagation thereby increases the data rate of communication by effectively suppressing Inter Symbol Interference (ISI). Companding schemes are widely employed to reduce the peak-to-average-power ratio (PAPR) in OFDM system. In this paper the performance of OFDM with Companding is described in Free space optical(FSO) link. The atmospheric turbulence in FSO system is described by the Gamma-Gamma channel model. The BER performance is done with OFDM scheme with and without A-law and µ-law companding scheme in FSO medium.