Analysis and assessment of the effects of phase noise in constant envelope multicarrier satellite transmissions

Constant-Envelope (CE) multicarrier techniques have been recently proposed in order to enable the use of multicarrier waveforms in channels characterized by severe nonlinear distortions. They are based on a phase modulation applied to the multicarrier signal, generated in the time domain by means of a real-valued DFT. Such techniques, known as CE-OFDM and CE-SC-FDMA, demonstrated their superior performance with respect to conventional OFDMA and SC-FDMA, when applied to nonlinear satellite channels, at the price of reduced spectral efficiency. An open issue still to be evaluated is related to the impact of phase noise on the performance of CE multicarrier systems. This is especially important in view of the use of EHF bands for broadband satellite communications. This paper aims at analyzing the effects of phase noise on CE-OFDM and CE-SC-FDMA, highlighting the different behavior of conventional and CE multicarrier signals in the presence of such impairment. Then, simulation results will be discussed considering two different phase noise masks. The performed analysis demonstrates that CE multicarrier signals have globally better performance when both phase noise and nonlinear distortions are considered. Moreover, the sensitivity to the phase noise is strongly dependent from the modulation order and the angular modulation index.