The present dissertation addresses to the subject of polarization implementation to MIMO satellite communication systems. It is a known fact that due to lack of scatterers near the transmitter (satellite) and space restrictions on the transmitter, a strong LoS is more often than not present, resulting in a very high channel correlation which, in turn, does not permit the creation of independent propagation paths. A very promising solution to alleviate, if not solve, the above described issue is the use of polarization techniques which are in place to offer additional degrees of freedom for exploitation. Only in recent years has polarization started to draw attention as a research subject. A plethora of surveys have been conducted since then, gathering results and information referring to terrestrial and satellite communication systems for indoor and outdoor environments, revealing that polarization have the prospect to be considered as a very useful and versatile tool. This thesis after building step by step all the needed theoretic background referring to wave propagation, propagation mechanisms, etc., concludes with the description of a Polarized 2x2 MIMO Land Mobile Satellite communications system model. The simulation of the system model follows with results for the system’s performance including BER, XPD and capacity.