Analytical Modeling of MIMO-OFDM System in the Presence of Nonlinear Power Amplifier with Memory

In this paper, the effects of nonlinear High Power Amplifier (HPA) with memory on Multi-Input Multi-Output (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) system are analyzed and a theoretical framework is proposed. The memory effects are represented by Generalized Memory Polynomial (GMP) model. Moreover, we derive an analytical formulation with infinite nonlinearity order and infinite memory length. The channel is assumed MIMO frequency selective and it is modeled as a linear dispersive channel with uniform power profile. We show that the decision variables of the nonlinearity distortion can be modeled by the complex attenuation and zero mean additive noise model. The analytical expressions for complex attenuation, mean and variance of nonlinear noise are derived and SER of MIMO-OFDM system using HPA with memory is presented. Excellent agreement between the analytical results and numerical simulations is observed that verifies the accuracy and efficiency of the proposed method.