Performance analysis of QPSK and 16-ary PSK systems in a land mobile regenerative satellite link

An analytical technique is developed to evaluate the error rate performance of quadrature phase shift keying (QPSK) and 16-ary phase shift keying (16-ary PSK) in a land mobile satellite communication channel. A regenerative repeater is considered. The effects of satellite nonlinearity and mobile channel on the performance of both systems have been considered. A frequency non-selective fading has been assumed. The combined effect of the traveling wave tube (TWT) power amplifier which exhibits AM/AM and AM/PM conversions and the multipath fading and shadowing of the mobile channel in addition to the additive white Gaussian noise (AWGN) are taken into consideration in the analysis. The effect of the TWT back-off from saturation which determines the degree of nonlinearity has also been taken into account. An expression for the error probabilities for both systems are derived and computed numerically