Error performance of uncoded and convolutional coded SC receiver over FSO channel with pointing errors

In this paper, the performance of intensity-modulated with direct detection (IM/DD) free space optical (FSO) system using the on-off keying is observed. Besides the gamma-gamma atmospheric turbulence degradation, the pointing errors and path loss are included. In order to mitigate degradation effects, the selection combining (SC) receiver is applied. After theoretical derivation of the bit error rate expression, the numerical integration is accomplished and confirmed by Monte Carlo simulations. Also, the BER performance is improved by using the convolutional coding, which is demonstrated by Monte Carlo simulations. Numerical results are presented and effects of normalized jitter, normalized beam width, propagation distance and number of SC apertures are observed.