Performance analysis of PPM variants in free space optics (FSO) communication system

In the world of wireless communication, free space optics (FSO) has gained popularity in exceptionally large bandwidth, unlicensed spectrum, and low power secure transmission. Despite the benefits, it is severely hampered by atmospheric turbulence, fog, haze, rain and other weather conditions. In this paper, the performance of different variants of Pulse Position modulation like Inverse Pulse Position Modulation (IPPM), Overlapping Pulse Position Modulation (OPPM), Shortened Pulse Position Modulation (SPPM) and Multi Pulse Position Modulation (MPPM) are studied for different weather conditions. It is seen from the simulation that IPPM and SPPM are better performer compared to OPPM and MPPM. Also, it is seen that the FSO system with PPM variants as modulation scheme has maximum range of communication of 4.5Kms for light rainfall and minimum range of communication for haze.