EDFA based adaptive RZ-OOK transmission for FSO communication

This paper proposes an erbium-doped fiber amplifier (EDFA) based adaptive return-to-zero on-off keying (RZ-OOK) transmission for free-space optical (FSO) communication. EDFA has the characteristics of average power limitation. Therefore, the transmitted RZ-OOK duty cycle is varied for accomplishing pulse power variations relying on determined average signal-to-noise ratio of received signal. Thus, the atmospheric turbulent effects can be compensated by this type of adaptive RZ-OOK transmission. The channel models with different turbulence effects are established, and the proposed technique is validated in simulation. The simulation results illustrate that the communication quality of system is considerably enhanced by the proposed technique compared with fixed threshold decision and adaptive threshold decision.