Abstract
This paper deals with a modeling of the phase shift keying (PSK) and the possibility of implementing PSK modulations using Mach-Zehnder modulators in the Matlab simulation environment. Next, a simulation of selected multi-level PSK modulations utilizing at the signal transmission in the optical transmission medium is executed. Finally, a comparison of modulated optical signals before and after passing a model of the optical transmission path is introduced, using constellation diagrams, signal characteristics, eye diagrams and waterfall curves of individual signals.