Complexity relaxations in wireless communication systems operating at the boundaries of components performance are foreseen. Due to this matter, a need to properly characterize hardware impairments degrading the performance of communications links has been recognized in previous studies. Statistical models might be the definitive tool for assessing the impact of these non-idealities. Particularly, the non-linearity of power amplifiers in multi-antenna scenarios was examined in this thesis. To this matter, a full revision of a novel method capable of capturing this limitation for a single-antenna and thus, a single power amplifier, was carried out. Thereafter, the strategy was to commence with the simplest multiantenna case and to increase the number of antennas and users until a general model was achieved. Results of the developed models in the thesis are provided concluding that these kind of approaches are valid to model the non-linear nature of power amplifiers in MIMO systems. Another studies of the evolution of this distortion when varying the number of antennas and users are also presented and analyzed
