It is shown that when an electrodynamic network model is used for a MIMO system, such a system can be represented as an antenna with nonlinear elements (ANE) consisting of linear and nonlinear multipole networks. The multipoles are described using component equations and are connected using systems of state and output equations. Furthermore, all nonlinear elements of the system (due to the presence of nonlinear de-vices in transceiving circuits, control and switching elements in radiating systems, non-linear loads, scatterers, etc.) are included in a separate nonlinear network, which allows for physical–layer MIMO system analysis and optimization time reduction, taking into account various nonlinear devices and reconfigurable elements.