Computer modeling of land mobile satellite communications channels is a valuable adjunct to analytical modeling for predicting and verifying communication systems performance. The simulations considered in this paper are concerned with the evaluation of the error rate performances of 16-ary quadrature amplitude modulation (16-QAM) and quadrature partial response signaling (QPRS) in a shadowed multipath Rayleigh fading channel. A frequency non-selective fading has been assumed. In this paper the effect of transponder nonlinearity has not been taken into account, since the aim of these simulations is to verify analytical results obtained recently in the same channel conditions. Simulation results shov, a good agreement with the analytical ones within the conventional permissible confidence interval that extends from half to twice the symbol error probability.