Performance of 5G candidate waveforms with non-linear power amplifiers

Wireless applications require the use of Power Amplifiers for signal transmission. Those are generally nonlinear devices, and there is a trade-off between efficiency and the signal distortion level, which degrades performance. Besides that, transmission waveforms suffer from spectral regrowth when non-linearities are present. Moreover, some power amplifiers also carry memory effects, which further contribute with unrepairable interferences. Here we investigate the performance of different candidate waveforms for 5G, namely, OFDM, FBMC and UFMC, in the presence of nonlinear devices, both with and without memory effects. It is also clear that to reduce the non-linear impairments, correction and compensation schemes are desired. Here, two possibilities are evaluated, the use of a digital predistortion structure, and of an iterative correction algorithm at the receiver.