BER Performance Analysis of an OFDM FSO Communication System over Atmospheric Turbulent Channel with Coherent Heterodyne Optical Receiver

FSO channel imposes enormous obstacles on adequate attainable performance levels because of its weather dependency which leads to system outages. In this paper a diagnostic methodology is introduced to assess the bit error rate performance of an OFDM FSO link using optical intensity modulation and coherent heterodyne optical detection receiver taking int° consideration the effect of sturdy atmospheric turbulence. The turbulence impact is demonstrated as gamma-gamma distribution and the performances are assessed as far as power penalty, CNR and BER endured by the framework because of the impact of turbulence at a given BER for a few framework parameters like turbulence quality, link separation, local oscillator control and so forth. It is discovered that with 4 subcarriers at 10 Gbps data rate, the power penalty is 6dB at a BER of 10−9 for a for a connection separation of 3600 m with 1mW power of both RF and Optical local oscillator. Overall performance may be improved appreciably by way of growing the quantity of ofdm subcarriers.