In this paper, the M-ary PSK system over the nonlinear satellite chann
els, in the presence of an arbitrary number of interferers and additiv
e Gaussian noise on the uplink and downlink paths, is investigated. Th
e effect of intersymbol interference due to transmitter filter is also
included. The bit error probabilities are obtained using the Gauss qu
adrature formula and a two-dimensional moment technique.