Analytical Evaluation of Nonlinear Distortion Effects on OFDMA Uplink Signals

In this paper we consider the evaluation of nonlinear distortion effects on the uplink transmission of systems employing OFDMA signals (orthogonal frequency division multiple access). Our results allow an analytical spectral characterization of the transmitted signals, as well as the computation of the nonlinear interference levels on the received signals. It is shown that the power allocated to each user has a key impact on the nonlinear distortion effects. It is also shown that nonlinear distortion levels are lower when just a small fraction of the subcarriers is used (i.e., when the system load is small).