Performance Analysis of STBC-FSO Communication System in Different Turbulence Regimes

The major concern in free-space optical communication is atmospheric turbulence which may significantly degrade the performance depending upon the level of turbulence. The use of spatial time diversity can mitigate the effects of fading caused by atmospheric turbulence. The simulation results show the application of space-time block coding in intensity modulation and direct detection system to improve the bit error rate performance. The improvement in terms of coding gain is maximum when the turbulence level is high.