Behavioral Modeling of MIMO Nonlinear Systems With Multivariable Polynomials

This paper proposes a novel behavioral model for multiple-input single-output (MISO) and multiple-input multiple-output (MIMO) nonlinear transmitters based on multivariable polynomials (MVPs). The main source of nonlinearity in these transmitters is the RF power amplifier, which is commonly modeled using polynomial models. The proposed MVP model is capable of handling the nonlinear effects of the RF transmitters, as well as the linear and nonlinear crosstalk between the input signals. At the same time, the developed model was optimized for computing efficiency without compromising its accuracy. The model was tested for MISO and MIMO wireless transmitters. The simulations and measurement results revealed that the proposed model gives excellent accuracy when modeling MIMO transmitters with different branch coupling factors.