Transmit Laser Selection for Two Hop Decode and Forward FSO Communication With Pointing Errors

In this letter, two systems have been proposed for efficient unidirectional free space optical (FSO) cooperative communication-one with only transmit laser selection (TLS) and the other using optical spatial modulation (OSM) along with TLS. Performance analysis of such systems for Gamma-Gamma (G-G) fading channels both with and without Pointing errors have been carried out in terms of outage probability and average symbol error probability (ASEP). Our proposed TLS system over G-G channel (with pointing error) yields a signal to noise ratio (SNR) gain of at least 10 dBm over the conventional FSO system.