First order statistics of semiconductor optical amplifier assisted optical wireless systems under log-normal fading

In this paper, we evaluate the utilization of a semiconductor optical amplifier (SOA) at the receiver of an outdoor optical wireless system for fade mitigation purposes. Due to its instantaneous gain response, the SOA provides saturating gain to incoming pulses and partially alleviates power variations between fade impaired and non-impaired instances of the received signal. We discuss this unbalanced SOA operation and analytically derive the first order statistics of the optical signal at the SOA output, giving emphasis on the scintillation index and the fade probability. Our results show that both the scintillation index and the fade probability are improved significantly by deploying the SOA, when the system operates in the weak turbulence regime.