Performance analysis of space-shift keying over negative-exponential and log-normal FSO channels

The average bit-error rate (ABER) performance of free-space optical (FSO) communication links is investigated for space-shift keying (SSK) over log-normal and negative-exponential atmospheric turbulence channels.SSK is compared with repetition codes and a single-input single-output system using multiple pulse amplitude modulations.Simulation results show that the signal-to-noise ratio gain of SSK largely increases with greater spectral efficiencies and/or higher turbulence effects.A tight bound for ABER is derived based on an exact moment generation function (MGF) for negative-exponential channel and an approximate MGF for log-normal channel.Finally, extensive Monte Carlo simulations are run to validate the analytical analysis.