The effect of solid state power amplifiers (SSPAs) nonlinearities on MPSK and M-QAM signal transmission

摘要

Simple four-parameter formulas model are presented for solid state power amplifiers (SSPAs) exhibiting both amplitude nonlinearity (AM/AM) and amplitude modulation to phase modulation conversion (AM/PM). Based on these models closed form expressions of symbol error probability for M-PSK and M-QAM signals transmitted through nonlinear SSPA in the presence of white additive Gaussian noise for a terrestrial link with a coherent receiver are calculated. Also the optimum values for the decision threshold levels and phase shift are calculated in order to minimise the error probability. The effect of SSPA input back off from the saturation point on M-QAM and M-PSK system performance are studied.