Study of complex-envelope behavioral models for radio-over-fiber link nonlinearities

Memory polynomials (MP) are demonstrated for modeling of RoF link nonlinearities, within the frequency range from 0.5 to 2 GHz, using a complex-envelope behavioral modeling approach. The model accuracies are studied for different RF frequency and input power cases, with the dependency of the MP model accuracy on the nonlinearity order and memory length parameters discussed. The experimental results show that the RoF link presents more memory effects at some RF frequencies and that the link phase nonlinearity tends to increase with the operating frequency. Excellent agreement between the measured and modeled results is reported for several validated MP models. In comparison with a memoryless polynomial model, the MP model performs significantly better for all experimental cases.