Comparison of Models for Multiple Nonlinear Power Amplifiers in Active Antenna Arrays

The methods used to model nonlinear power amplifiers are many and varied. With the introduction of active antenna arrays as a solution to increasing the capacity of cellular networks new strategies need to be developed to model their multiple signal paths. Models for power amplifiers in active antenna arrays will be required to have similar performance in terms of speed and accuracy as before. To achieve this, will require a reduction in the number of coefficients in each signal path relative to the number of PAs in the active antenna array, or alternative modeling strategies. In this paper we will present some of the reasons for requiring the ability to predict each PA output in an active antenna array, a shortlist of models which can be used to model the outputs of all PAs simultaneously and efficiently. Finally the relative performance of these models are compared in terms of their size, accuracy and speed.