“…In general, the interference analysis can be performed at any distance from the signal source antenna. In the case of a near-field, the influence between the individual elements of the multi-antenna system can be investigated [ 20 , 21 , 22 , 23 , 24 ]. In the case of a far-field, inter-beam [ 25 , 26 ], inter-cell [ 18 , 26 , 27 ], or inter-system interferences, i.e., the coexistence of different systems and networks [ 9 , 11 , 28 ], might be studied.…”